It's WCS, so people will always bitch. I quit it a while back cause of all the bitching, started GG ... no more bitching (except when Drew is on, but that's what the mute button is for).
I don't know the current races, but I'm sure it boils down to the same thing it was before the orange update. When I unlocked all races I pretty much picked 1 race to adapt my playstyle to. The race was strong, but not OP on it's own. The thing that made it OP was the fact that I didn't (have to) spend money on xp tomes anymore but could spend it on defensive/offensive shopmenu items. While I was levelling I was up against people that did the same I ended up doing, fucking hard to kill, but felt much better then killing some random noob and the xp was lots better as well.
There is no way to completely balance a wcs server, unless you stick to the 4 original races maybe (human alliance, night elves, orcs and undead). Back in the CS days I was admin on a popular 4 race wcs server and it was hella fun, other servers with more (10-20 back then) weren't as good imo, mainly also cause of balance issues.