I know I posted in this early, but I think I'm going to do it again.
BRP has a couple of big virtues; its relatively intuitive, can pretty much put almost all the numbers you're going to need to routinely know on the sheet, and is relatively easy to adapt to most genres (it can be adapted to others--the full blown version of Superworld Steve did shows that--but it requires some heavy lifting). Its not quite as one-single-resolution as some people will sell it (the traditional version had three: they might all use percentile rolls, but attribute rolls, resistance rolls and skill rolls aren't the same thing. Some versions try to compress that--Mythras, for example, has reduced everything to skill rolls (though whether there's a price for that is something that can be argued)--but the full traditional version has all three.
I used some version of it (mostly RQ or Superworld) throughout a lot of my gaming career. I want to make this clear because its not a system I'm intrinsically hostile to, and not one I'm not familiar with. I want to do this because I'm about to mention a number of reasons I don't really use it any more.
1. I'm no longer a big fan of big linear die rolls such as D20s and D100s. They're easy in some ways, and make probabilities clear, but they also (mostly) require you to use pretty linear modifiers in effect (you can mess with divisors or multipliers, but that tends to reduce some of the convenience of a percentage system). I'm really much bigger plan of either 3D6 or die pool systems.
2. Its really hard in most versions to get away from random attribute generation. This is because almost all forms have a pretty sharp-edged and strong breakpointing, so if you go to any sort of point distribution you'll almost certainly end up getting a lot of those breakpoints hammered hard which can be unappealing on a number of grounds. Arrays are a little better, but its still not ideal.
3. Like a lot of old school systems, BRP typically doesn't give you much character definition tools outside of attributes and skills (and paranormal abilities for those who have them). Some things simply don't fit in that model, and I'm used to having some sort of talent/trait system these days.
4. As a default, BRP can be more lethal than I generally want these days, and its not easy to address without over-fixing it. A Savage World style metacurrancy system would work if you can get the numbers right, but its not actually trivial to find a model there that's sufficient but not excessive.
Summary: Its a system that, when it came out, was revolutionary in many ways; it was what I hopped to when I found D&D progressively unsatisfactory on a number of grounds. But from my point-of-view these days it usually shows its age, and some of the problems with it are not trivial to address.