Man, that demo sounds great.
Guys, I was never an el84 fan myself 'til I got my 5:25 - it sounds so good that I really couldn't tell what kind of output tubes it had. The cleans are just so nice and chimey and overdrive is smooth with a nice edge on it.
What I don't like about my MESA is how hot they run the el84's: 400v on the plate at about 32ma of bias current. Even with the coldest JJ's I could get it was still over biased. I ended up modding the bias circuit on mine. MESA says it's fine running that hot, but I went through a couple pairs of MESA branded el84's in days. I switched to JJ's and modded the bias circuit, haven't had a problem since.
Anyway, if they're running 'em that hot in this amp, it may be something to consider.