BLuRay, I read your post about the 4 Stroke and think it throw a lot of light to my searching, thanks for sharing!!- I had the chance to try the OB1-500 with the OBC210 mini and was amazed by it's tone and overall carachter , I digged blending the two channel with the drive full closed and even there the amps gains in presence, body and fulness, and I really didn't care dialing more drive cause things started to be to fizzy for my ears. It was my first contact with non class D amplification and I am a bit concenrned on the OB1 to be a 1-trick pony and get lost in the mix in some situations. In the opossite a fear the 4 Stroke not having the OB1's authoritive weight it's sound provides. The store doesn´t supplies the 4 stroke but I will test it in other store but paired with a 410 Hartke, so I will not be able to make a direct comparisson of both.
I'm a bit surprised not to find direct comparisons between these two models since they are in parallel production. So I will have to fine tunning my ears and auditive memory to decide wich amp will replace my average class D amp.