Glai,
I don't know how the A308cr pre-amp and amp compare to the Tri-Vista or KW500 integrated's.
I'm sure a MF dealer or the US distributer, Signal Path, 'http://www.signalpathint.com/', could give you an honest evaluation. They've always emailed me right back on any questions I've had.
Before they were discontinued (just recently) their price was $2800.00 for the pre-amp and $4000.00 for the amp. They were made in England and have the Choke-Regulated power supplies. From what I understand, they are heads and tails above the A3.2 cr pre-amp and amp.
To give you an idea of how good the amp is supposed to be, I called Sound By Singer to see about trading in the amp for a conrad-johnson Premier 350, $8,000.00, and the salesman told me to keep the amp, that I didn't know how good it was. If the salesman gave up the commission on an $8000.00 purchase in telling me that, what do you think?
There are reviews on the internet that rave about it. It's supposed to one of the most neutral amps on the market. Like I said, after hearing them while waiting for my Tri-Vista 21 DAC to arrive, I traded my Krell pre-amp and amp in the next week on them.
Chuck