Jbl gto vs. us amps md42 vs. old school ppi pcx480 vs. other good 4 channel amps...

I need a good 4 channel amp for my mids and highs around 4 x 75 rms. I looked at the jbl gto series first because of the price and good specs on the website but found conflicting specs on other sites like ampguts, showing the db level at 80dBA (1 Watt, 4 ohms) when on the jbl site it says over 100, also the dampening factor is a little over six on the ampguts site, along with a higher thd than the jbl site. I have seen the 80dba rating and 100db rating on a variety of websites so am confused on this issue. If anyone knows what this means, please fill me in. Then I saw a deal on a md42. Looked at the specs, seemed good and efficient, but someone mentioned on the site that they had to recall some of the amps and I have been unable to find a convincing number of reviews that would lead to purchase this amp. Lastly, I came across and old school ppi, which I have read are pretty darn good. Great specs, but am a little worried about it's efficiency because it is a little outdated. If you had to choose between these three, what would you go with? Or could you mention something I should look for. I am trying to keep it below $250 (new or used). My mids and highs are jl audio and was also thinking of getting the 300/4, but have read mixed reviews on that amp. Someone please enlighten me, lol.