I love EBS and Mesa amps (I have a Fafner, Walkabout and Big Block 750). You can't really go wrong with either brand.
I did have an M6 Carbine for a while, which was a much more 'modern, clean, aggressive' tone which I understand is not a million miles away from the sounds that can be had with the Subway channel on the TT800. I did end up selling the Carbine because it was actually 'too clean' for me and I needed to sell the M6 to get the Big Block, which had been my dream amp for about a decade.
The two channel flexibility of the TT800 would be deciding point for me, though I would probably be on the Boogie channel 90% of the time.
If going the Mesa route I would certainly consider the WD800 as well.