Unfortunately, my only experience with the M3s was a few years ago on some small cheap bookshelf speakers, thus, I really didn't get a full feel of the amp's character.
Just curious, did the M3 sound thin or produce any glares at mid-highs with the heritage series - or, did it sound sweet, velvety and smooth through out the entire band. Also, how was the bass? I read some reviews online that the bass was a little weak and thin on the M3, and other opinions that say it is just right. Do you remember how the bass was on the LaScalas.
The only reason why I'm avoiding tubes is because I'm lazy. The only affordable tube amps I've come across, that actually have an the auto-biasing feature, utilize push-pull topology, whose upper frequency glare really turned me away (may be it was just the specific ones I've hear) - although they do display authority in the lower end of the spectrum. Single endeds on the other hand severely lack bass control, don't have very long tube life, and do not typically come with auto-biasing (even so, SE topology's midrange is un matched to anything else in the world PERIOD). I know that bi-amping SE with an SS like B&K is an option to consider, however, I do not want to spend more than 3g. If you have any tube or biamping suggestions for under 3g, I'd be happy to give them a shot (unfortunately, I do not want to get used equipment - I've my share of issues with this in the past)
Thus, I was just wondering how NAD M3 might sound.