In the beginning I was serverely infected by LBA, but I've been through re-hab and am now cured, also like ex-smokers, I now have an aversion to lens collecting, plus my bag is much lighter and my finances less strained!
Although I have some primes (and have owned many more in my LBA period), I find that for most purposes I use zooms, with two major exceptions.
1. I use a macro lens (FA 50 macro) because it has very specific uses that zooms cannot satisfactorily provide, plus they usually are the cream of the crop, IQ wise, of all lenses.
2. I find that for my long telephoto use, I find a 300mm prime (FA*300 f4.5), plus a 1.4 TC for that extra reach, is almost as convenient as a long tele zoom, but IQ is a huge improvement over long tele-zooms, much more so than in the mid range where top quality zooms are not that far behind primes in IQ, and in some instances are as good, if not better, in many areas (e.g. DA 12-24 v DA 14).
Personally, I find that using primes in the wide to mid tele-photo region is a royal pain in the A. Apart from macro and long telephoto use, I never seemed to have the right focal length on the camera. So I've parted with most of my primes and don't miss them one bit.
The only area that I currently find unsatisfactory is the range between 50mm and 300mm, I have owned and tested many zooms in this region and none have really met my requirements. These have been the Tokina 80-400 mkII, 80-200 ATX-Pro, Sigma 100-300EX, 70-200 EX, 50-500 EX and Tamron 70-300 Di LD macro. The Tokina 80-400 was quite decent, but I preferred to use my FA*300 and TC for the longer reaches and the IQ was still a way behind my desired level, in fact the cheap Tamron 70-300 Di is probably equal (apart from the occassional PF), and a lot cheaper, it's my current (temporary) solution.
I have my fingers crossed that the long awaited DA*60-250 will fill my need in this region. From my recent poll, I don't seem to be the only one! I just hope that it does finally arrive this summer.