Is an isolation transformer better than a power conditioner?

I use a PS Audio P20 for the last few years and have found it to be a great addition to my kit.  Larger sound stage, more micro detail, lower noise, also, because of the low impedance, there is more openness on loud dynamic passages.  I am using Auidioquest Hurricane power cords throughout my system and have a dedicated 20 AMP circuit to the P20.  From what I understand you can demo any of the PS stuff for 30 days and send it back if you don't like it.  I have done A/B with and without the P20 and definitely prefer the P20.  

I took Charles advice a while back and now run Equitech on 4 systems. Best audio advice I ever got. Huge improvement IMO. (I had tried Shunyata and PS regenerators), There is a reason so many of the big boys use Equitech.

I have used isolation transformers and preferred the sound without. The sound was less alive. I use a PS regenerator and prefer that to without. Have fairly typical power usually reading about 2.7% THD.   

You may no need either. You equipments power supply can generally clean up AC, so if you have no line noise that is often in frequency ranges power supplies are not designed to filter, special power conditioning and cables may not do much for you. Isolation transformers are less expensive and often do the trick, it depends upon the noise and the transformer. Good luck sorting it out, no one who doesn't know the power in your area can give you a perfect answer though, IME.

Would clarify that Equitech is "balanced" power transformer. Not conventional transformer. Noise gets canceled by balancing power to +60/-60 instead of +120/0 (not a completely accurate way to describe it). Most of the noise affecting your system is produced by the reactive power generated by your own gear (depending how terrible your wall current may be). The  regenerators do nothing to mitigate that problem. Plus they limit current so you can't use it for your amps. You can (and should) plug your amps into the Equitech. Dynamic range is not limited (assuming you have the right size unit) and the noise floor is lowered dramatically.