Moray,
Interesting, I have asked a few people about the CF's efficiency and most said they felt it was slightly overrated for instance CF-3 more like 95 as opposed to 100 as stated.
The other lines such as Heritage I believe may be as you say, but this is just what I have read.
WVU80,
Have listen to a tube amp, some people prefer the sound......I do, but everyone has different taste
Bob