Determining the "flavor" of the game is very important when picking and choosing mods and house rules, especially for combat.
In D20, the idea is that "heroes" run around killing things, taking their stuff, and learning from it which is why Base Attack Bonus goes up every level...the idea is that killing things makes you better. If that were the case, 90% of the world would be 0 level since they never kill anything, much less sentient beings...
I, personally find that idea repugnant.
In BRP the idea is that as you do things, you get better doing the things you are successfully accomplishing. I like that, it seems to fit reality much better.
Also, in BRP, the idea is (generally) not "heroes" running around killing things...it is morally ambiguous (no alignments) characters interacting within their reality (the setting) in the manner that is most advantageous to their goals (the adventure/campaign).
I find BRP to be far superior to any other system for modelling combat. What I have experienced so far is that combat sucks. After a fight you are tired, injured, weapons are dirty, equipment is broken and it generally leaves you feeling angry at your enemy for fighting you and forcing you to kill them. Reproducing that is the job of the GM.
In game terms, very, very few people that have been shot do much else except sit there and bleed. With blades, much the same thing happens, although shock isn't as much of a factor, although a trained swordsman or knife fighter can do as much, if not more damage with a single thrust/hard slash than most pistol rounds.
Many people think that "old" weapons (knives, swords, spears) are somehow less capable than guns...that is incorrect. Modern firearms have superior range and require less skill than archaic weapons, but an expert melee combatant can kill you just as dead as someone with a firearm...hence why people with guns try to stay far away from those with
only knives
Also, moving back on topic (sort of)...BRP's lack of "hit point" advancement means that unlike D20 where a character can get shot, stabbed, fireballed and still move and fight, a BRP character will avoid getting hit, placing far more importance on not getting hit and setting up opponents for the "big one" that will take them down quickly instead of whittling down their opponents several hundred hit points.
When taking a group of D20 players and moving them into BRP style combat, most of them will whine and complain that their characters suck and they can't take a hit. They will then charge into combat and usually have their @$$es handed to them. Afterward, they will learn to respect combat and place it back into it's rightful place that it occupies in the real world.
Combat is either the first option (attack from ambush to kill your opponents before they can react so that you stay safe) or the last option after diplomacy, appeals and reason have all failed and a conscious decision is made to engage them because (in the mind of the combatants) there is no other way to achieve their goal.
Sorry to threadjack.
-STS