W
Made a personal rule to never give neg rep, since IMO it stifles free speech.
This is the only forum I've ever been on that utilizes it. When it (the rep system) is pure, it is a useful tool. When it gets perverted by rep whores, it is meaningless. I'd rather see the Ebay-style feedback add-on that I know VBulletin is capable of using be put to use here instead of the reputation system.
I like it. Let's me know if I'm contributing in a way that folks like. Also lets me see who the big contributors are. Much better than looking at post count.
I'll second this. I find it useful and it's part of the INGO culture. Is it necessary? Probably not. Are their other things out their working better or worse? Sure. The only thing I would say about changing things like the rep system and group buys etc., is that care needs to be taken to avoid changes which would drastically effect the culture of the site, which is what brought most of us here in the first place. I'm not saying either of those changes would damage it, just throwing it out their to be considered.