I have had the pleasure to audition a Vincent SV-500 recently. Lower end of your price range. This does have three tubes in the preamp however--but they will last for many many years. This is a very well thought out integrated where money was wisely spent as far as parts selection goes. Build quality is excellent. But all this would mean nothing if it didn't sound good. IT DOES.
I placed this is one of my systems where is displaced a $4000 integrated amp. Was I in a hurry to move back to my reference? Not at all. I was amazed by the generous sound stage this amp produced. It never sounded short on power. Amazing the kind of juice you can get out of a single pair of high quality output transistors! The amp is fundamentally neutral. Not at all veiled but no edge to the music (which I am intolerant of). Have not heard your amp but can't imagine you would not be pleased with this unit.
On the other hand, if you just stuck with the Cayin I never viewed the cost of tubes even now a deal breaker. (I once had a tube integrated with 14 tubes--now that would be a deal breaker).