My 3500 arrives tmrw. The reason they are priced so competitively is that they are using open tool boards and just beefing them up. For example the3500 is spec'd as a Zenon 3800 and the Flatline version (fl2) did right around 3.8-4k. The AL has beefed up caps and fets does 4.5k.
The 5000 which is specd as 4.8k is board. The Crescendo
Encore version does 4.5k while the AL does 5.5k. Again, stronger than stock parts.
I did a lot of reading before I bought one. The 8.5k is also the Ts 8.5k/tfe etc. I couldn't confirm but the 6.5 is likely the ts 6.5k.
They don't hide the fact that they are just beefing up existing Korean pcbs