what's going on with specs?


I'm having a hard time buying a power amp. I'm in the 5-10k range and whae I'm finding are things like PS Audio BHK 250. Specs show 250@8ohms and 500@4ohms. Then the Parasound JC5 shows 400@8ohms and 600@4ohms. Looks like PS Audio doubles at 4 ohms which makes me think it's a stronger amp until I notice the PS Audio spec is at 1 kilohertz and the Parasound measures 20 to 20 kilohertz. That is very confusing and I don't understand why PS Audio doesn't give full power measurements. Anyone with knowledge of these two brands or others. I have the Elac Vela 409s to drive. 
128x128dconfalone
If you’re discussing Watts, the room size, its acoustic liveness, and most importantly YOU and your musical choices and volume demands all matter in determining how much amp you want. SS amps generally have low output impedance and ones on your list have high current, so the 3.4 Ohm minimum of your speakers will not faze any of them nor cause major tonal surprises.
Even a Naim 80 W amp can deliver incredibly dynamic music reproduction. People love the Pass Labs 25 W amp. If you’re looking for nightclub volume you need all you can get…and bigger speakers. 
I have a JC5 running some Revel F208s and it sounds amazing. My buddy has a BHK 250 running some Sonus Faber Olympica Nova V's and it also sounds amazing. You need to figure out what you want. Both amps are different variations of awesome.
It’s like the internet is a new technology for most of you. Youtube -> enter name of amp -> watch vidya
@dconfalone
There is some reason a Boulder amp is going to sound better than a Sony receiver and it must show in some measurements.
You are mistaken, our audio acuity is much more complex than current science can measure. 2 amps that measure the same but are designed differently will sound different. Also, our individual audio preferences are different.  

The best way to evaluate a component is to demo it in one’s own system. If you cannot, then you research reviews of the component while taking into account the rest of the audio chain. Component to another component comparisons gives you an idea on which is the best price/performance. After that it’s just a best guess what you’ll like- then roll the dice. Hope I didn’t miss any steps.

If you buy used, you can sell it and not lose much $ provided that the component is marketable (enough demand).