The XV15se would not have more output than the VTF3 mk5. According to available measurements, the VTF3 outperforms the XV15se. Also, with respect to amps, these topologies have their advantages and disadvantages. BASH amps are a class A/B and D hybrids. ICE and Sledge amps are class D amplifiers.
Here is an article that discusses those amplifier classes.
I forgot about the new versions of the VTF 3, and VTF 15, yes they are vast improvements on the former models according to CEA 2010 measurements. However, the new PSA V1500 has every bit of the output of the VTF 15 mk2.
I'd rather go with the PSA V1500. You're welcome to disagree, but I've done variable tuning before, and with the advent of advanced RC, such as Audyssey I don't think it's all that useful anymore. I just want to plug up the sub, run Audyssey, and be done. That's just me though.
Bash, and Sledge are the Ford and Chevy of sub amps. I've had both and haven't had much bad to say about either. Generally speaking a good sub maker (which PSA and HSU are) will match up the right amp for their design.
Ice is a bit of a new player who PSA is gravitating to. Among other things PSA can get more power per dollar, and have a total system made in the USA (if that means anything to you) which is kinda cool if you ask me.