Hard to believe, but I am now starting my 4th year with the Dex. I have been a T1 for 31 years, and after some missteps in the first year (back then it was still urine testing and pork-based insulins...enough said!) I have been in very tight control and have no complications to date. I do not use a pump, but I was very diligent about fingersticking...probably 12-15x a day. But three years ago I had a low blood sugar episode that prompted my endocrinologist to suggest a CGM system, and with that I started on the original Dexcom. Here are some thoughts after three years on the system:

PROS
Much more awareness of my BG trends following different activity levels, meals or insulin dosages. That was an eye-opener my first few months on the Dex.

Activities that were problematic for fingersticking (skiing, golf - since you grip the club blood would continue to gush out of a fingerstick for several holes due to the grip pressure, gym workouts, business meetings, movies or shows) were now significantly better. The example I give is standing at the top of a ski run, bundled up, and wanting to make sure my BG was ok before going down. That was impossible to do with a One Touch because the outside temp was too low, not to mention the fact that you'd have to take off gloves and get all the "stuff" to do the test. With the Dex it is simply a matter of reaching into a pocket.

No more "overreacting" to high blood sugars...this is related to my first point above. I could now see where higher blood sugars were peaking and starting to settle out. With only fingersticking, sometimes I would over-medicate to get high blood sugars heading downward.

Lower stress levels related to blood sugars. Just being able to look at the Dex and see that sugars are in a normal range with a flat arrow is relaxing...or rather it at least reduces the stress levels about maintaining healthy blood sugar levels.

The Dex has made me aware the fingersticking is not fool-proof. Often times if I get a fingerstick that is materially different from the Dex reading, I always fingerstick again to check. The One Touch is not perfect! If your fingertips are not clean then there is the possibility that there is some sugar residue there that can make the fingerstick inaccurate. My guideline is that if fingersticking is materially lower than the Dex, the fingerstick is probably accurate and the Dex is slow to catch a decline in BG. I don't bother to recheck the fingerstick...I treat the low blood sugar. If the fingerstick is materially above the Dex, then I don't do anything until I fingerstick again to see if the value is closer to what I'd expect given the Dex's reading. I NEVER GIVE MYSELF INSULIN BASED ON A SINGLE FINGERSTICK READING...that is dangerous because even with normal blood sugars it is possible to get an inaccurate high reading on a fingerstick.

For long drives, monitoring blood sugars are easier. I always fingerstick before getting behind the wheel, but for monitoring trends (i.e. watching for down arrows) while on the road it is useful to have the Dex.

Customer service has been excellent with almost no exception. Sensors have been replaced without question when I have called with problems.

Net net, my highs have been lower, and my lows have been higher than before, and my A1C's have continued to be in the same ranges that I had when I fingersticked frequently.

CONS
I have had every possible frustrating experience with the Dex over the past 3 years:

The sensor that just goes bad for no reason...instant "failed sensor"

The "???" episodes that are much less frequent with the Dex Seven Plus than they were with the original, but still happen.

The inaccurate low readings at night that keep me and my wife awake. Sometimes the only way to get some sleep is to turn off the sensor. When these first happened I would over-correct the lows by eating or drinking juice just to get the low alarm to stop. Then later that night I'd have high blood sugars from the over-correction.

The static electricity reset....all of a sudden the sensor goes dark.

The tape that starts coming loose after 4 or 5 days.

The sensor that just never seems to be accurate, or even close to accurate. Usually I give a sensor two days before killing it and calling for a replacement. Sometimes you never know...I've had sensors that barely worked the first day and they somehow become perfect for the remainder of the week.

Related to the "low alarm at night" comment above, I've had periods where the sensor flat lines at a high or low level for an extended period of time. Frustrating when it is either low or high. Usually a flat lining sensor is on its last legs and I kill it.

In general, the sensors that make me think the system should be called the Dexcom Five or the Dexcom Six...sensors that start slow and end prematurely. On occasion I have had sensors that perform really well and the adhesive also works well, and I have used 9, 10 or even 11 days. But those are pretty rare...usually performance for me starts to degrade and I've never experienced the great performance in the "extension period" that others here have seen.

The system is expensive, though worth it to me. Blue Cross has covered it for me since day 1, which helps, but it still is a lot of $$$ out of pocket.

SUGGESTIONS TO DEXCOM

Please make the receiver smaller. Holy Toledo, three years now and there has been no improvement in the form factor. Make it an iPhone app or at least make the receiver smaller. My original One Touch from the 80's was gigantic, and so was my first cell phone, but these days to have a form factor that stays unchanged for 4 or 5 years is terrible.

Have a Mac version of the software. I don't use the software much at all, but when I need to (when working with Customer Service to diagnose a problem with a sensor) I need to borrow a PC to upload. I don't have the know-how to put the software on my Mac using parallels or whatever.

Use a more universal charging system. One time on a business trip my receiver lost power and I couldn't restart it using the reset button (stick a pencil or paperclip in the hole in the back). Customer service said I had to stick the charger in it...problem was I didn't have the charger with me so I had no Dexcom for a couple of days.

On the receiver, have a countdown reading so I know how long a sensor has until expiration. I sometimes forget what day or what time I started a sensor. Would be great to be able to find out how much time a sensor has left.

When you re-start the receiver after shutting it down, please eliminate the "test" of the alert function that is loud enough to startle someone in another zip code. I once restarted my receiver in a quiet room (I can't remember why I shut it down) and the noise that the receiver made when it restarted had heads all turned my way.

Did I say make the brick receiver smaller?

CONCLUSION

Hope this summary was of interest. On the whole, I would say I am glad I have the Dexcom, though I wish it were better for all the reasons above. If I were to give the Dexcom a rating, it would be something in the range of 7.0-7.5 out of 10.0. At times it is frustrating, but on the whole it beats not having it. When there is a time that I don't have a sensor attached (like when I kill a sensor and want to wait until the next morning to start a new one) I really miss having the sensor for what it provides, even though I like not having the bulky receiver in my pocket. I will keep going now into my fourth year (this is my second receiver that I got about a year ago...my first receiver started losing charges quickly and the receiver was getting weaker) but I hope some of my suggestions above will be incorporated in whatever new version comes out (whenever that date may be).