The maps are pretty bad in this game overall. Very interesting to me that so many people hate Complex though...that's one of my favorite maps. The only maps I can stand anymore are Complex, Exile, Meltdown and Vortex. I used to like Ragnarok but it comes up almost every time I play BTB or CTF, so I'm sick of it. Haven, Solace and Abandon are particularly awful.
Complex is hilariously bad for Flood. First time I got this map in that playlist, I naturally ran for an elevated area and found pretty much everyone else going for the roofs to. Suffice to say we stood there and took casual potshots at the two poor flood scurrying around at ground level.