I tried the Dexcom in 2009 for about 5 months, but I quickly abandoned it after I had lipodystropy on both sides of my abdomen. The doctors (and Wikipedia) said it was because of the insulin, but I've been using Novolog forever and had the pump for four years at that point, so I'm not sure why it would magically start happening in the span of one week. I stopped using Dexcom, but I continued using Novolog and the pump, and I haven't had problems since then.
My guess is that doubling the amount of needles in my abdomen caused this, and the Dexcom needle was fairly long (and very difficult to insert). Only one side of my abdomen has gone back to normal.
But now, I'm trying the Revel pump and CGM. I'm not happy with the needle length, and it has caused bruising and bleeding, but I am happy that 1) it covers much less real estate than the Dexcom, 2) the monitor is built into the pump, and 3) the sensor has an inserter. However, I'm mystified that the transmitter is allowed to naturally flop around, and you have to use a massive IV3000 bandage to secure it. Incredibly clumsy design. Luckily, I've managed to use a simple piece of medical tape to secure the transmitter to my body.
Another thing: If you don't angle the insertion properly (close to 60 degrees), then the insertion point is exposed! Plus, I've had a lot of bleeding around the insertion point, and the blood dries up underneath the base. Not aesthetically pleasing.
Overall, lots of pro's and con's with both Dexcom and Minimed. Not sure why they take so long to improve their designs, especially in this day and age of advanced technology.
Well, Medtronic has a new sensor, the Enlite, which has been in use in Europe for a couple of years now, which has a tape built in to secure the transmitter. And it lasts for 6 days instead of 3.
But, of course, it is lost in FDA wasteland hell, so no one knows if or when it will ever become available in the US.
Neither one of the CGMs is as good as I would like them to be, and yes, I would really like to see both companies working on improvements. I'd like to see more accurate meters for that matter! But with the FDA the way it is, and the healthcare industry the way it is, I advise you not to hold your breath.