You think thar a single surface system is more faster , i'm not really sure, peraph in old PC. But with a single surface I can't do all that EPS do ...
Single surface particle systems are still a lot faster on my Athlon XP 2700+ and Radeon 9700 Pro. I'm not sure what EPS does that you couldn't do on a single surface, but Particle Candy manages a huge range of parameters and effects. It's a pain to code it, of course, but ultimately I couldn't use a particle system that wasn't single surface, because it would just be too much of a drain on the speed.