I have an EP500, but I also built an HT for my in-laws and for them we purchased an SVS PC Ultra13. Keep in mind these are 2 totally different sized and shaped listening environments, so any direct comparison between the 2 subs is difficult.
I'm splitting hairs saying this, but in general I do prefer the sound of my EP500 to the SVS. I find the EP has a more 'musical' or 'richer' sound to the bass than the SVS. However the SVS is capable of going seriously deep and loud and is quite adjustable with the settings included on the sub vs. the EP. Both are amazing subs and both keep me smiling all day long.
Also keep in mind my EP500 is not the latest design that Axiom offers, and the SVS my in-laws have is the previous BASH amp design which they have now updated to Sledge amps with DSP - I have no idea if that's any better or worse than the previous BASH design.
To be honest if I was in the market for another sub right now I don't know what I'd pick! There's so much to choose from.
Not sure if that helps you, but that's my 2 cents for the day.
