Thanks for the advice. I had already read the review at Techpowerup, and I also found it was "good for the money". I've ordered two of those Antec and will build two systems around them. I'll check the noise, but it's not critical in this case: they are for the nephews and all they want is higher FPS in their games
My problem is that it's becoming increasingly difficult to find Seasonic made PSUs around here (Spain) at a reasonable price. Usually I can pay for them, since I build high-end rigs, but I need an alternative for those cases when my customer has a limited budget. It's nice to know Delta is realiable, even if noisy.
EDIT: I couldn't find the Enermax EMD425AWT model here. The Enermax EMD425AWT II (note the II at the end) is about twice as much as the Antec VP550P and 125W less. I'm afraid I need those extra watts for those gaming systems and I definitely do not need modular cabling (that's a luxury I can't quite understand from a functional point of view). I know Enermax is very nice, but I can only easily find very high wattage models from them (800W and up), which I rarely need.