I used R and NPH for the first six or so years of diabetes, and then used R and Humalog for another ten years before switching to Lantus and Humalog and then finally the pump.
I attempted to count carbohydrates during my later years on NPH and found it difficult because it was impossible to tell what was being covered by the peak in NPH. At the time I took two shots of NPH a day, one in the morning and one before bed. (During the first eight or so years of diabetes I took NPH before breakfast and dinner, but this caused numerous nasty lows, and changing it to bedtime fixed this.) I had to eat snacks between meals and before bed to accommodate the peak. I could not skip or even delay meals (even by only half an hour) without going very low because of the NPH peaks. Using R, I took it about half an hour before eating. Trying to eat out at restaurants (which usually meant a delayed meal) was a huge ordeal.
I had a good A1c while growing up (in the low 7s usually) but, like Holger said, had many, many lows to pay for it. I think taking NPH three or four times a day might smooth out the peaks and make control easier. When I was on NPH I didn't take any insulin at lunch because this meal was covered by the NPH peak. This peaking action (that, according to research, can vary by something like 50%!) is the huge drawback to using NPH as a basal insulin. It's like getting random extended boluses at various points in the day, which is why snacks are usually needed.
Correction boluses might be difficult because of how long R lasts in the system (something like six to eight hours), making it very easy to stack insulin.
Sorry I sound so negative. I just don't have any positive memories of R or NPH in comparison to MDI or the pump. But there are some on this site who do manage to somehow gain good control and even flexibility while using these insulins. I suspect for anyone diagnosed as an adult who manages this, that their pancreas might be helping to smooth out some of the rough edges. But if this is the case and it works for someone, then that's great!