As promised, my after gig thoughts
I was very impressed with the BH500 and two 2x12 cabs, the gig was in a fairly small pub but there was a great crowd there which made the gig very enjoyable

The amp has a preset feature where 3 preset tones can be stored, all you do is dial in a tone and press the particular button for a few seconds until the LEDs light up and thats it, as easy as setting a car radio, I set mine for preset 1 to be clean finger pick tone, 2 for a slightly dirtier finger tone and 3 for a rocky plectrum tone, I used my Fender USA DLX P for the entire gig .
You can also use the conventional EQ by turning the presets off, the presets can store the 4 band EQ, a Tweetertone setting, a Valvetone setting, a compressor (spectratone) setting, a gain setting and one of two contour curves, it is very versatile and nice to just push a button and get another tone, great for when going from say a blues song to a rock song
The on board tuner is superb as is the LED for the gain level .
Now for the most important item - the sound;
I found myself playing much better and with more confidence than previously, possibly due to the increased tonal range and better clarity of sound than my GKMB210, the other band members noticed a better sound and they reacted to it too saying that my improved sound drove them on more

I could turn the bass EQ up without fear of excessive boominess, the 452 square inches of speaker area from the four 12s certainly filled the pub with lovely bass tone .
So, all in all a big thumbs up from me
ps
The fault with my GKMB210 turned out to be the jack socket soldering come loose on my MIM P, I had put a new scratchplate on it a while ago and must have inadvertently streesed the wire when tightening the jack nut, I am still happy though as I had been gassing one of these TC rigs !!