Steam is annoying, makes the game lag (Main - steam VS alt - non-steam, main 3% loading alt fully loaded)
Steam sometimes randomly screws up, showing me to be offline even if I had active Internet connection and able to browse websites etc.
Steam takes up RAM, 80,000k+ and I only have 2GB, compared to Window's own processes it's huge, and I have to have it running in order to play with my main. (DUH!)
Yes it is safer to use, but I never tell my pw to any1 anyways.
Yes the trading interface is buggy but good, but my alt can use steam instead.