Hello guys. I removed all the risk and ordered one for myself. I'll do a blog post on it based on actually having it in my hands, unlike that other website mentioned in this thread. Diy599.com is legit. Oliver does this for passion, not for money.
With all that said, I have beaten the heck out of this amplifier for about 3 weeks. Testing with the Icom IC 705 and the tx500 on FT8, js8, einlink vara 2750, ... It's pretty freaking incredible!
My initial plan was to buy the Hard Rock 50. I believe this is superior and a much better value. PA 500 will be featured in my tx500 update video, in the coming days.