Two very different animals, really. I have a friend in the DC area with an M3. He loves it, hasn't had any issues with it to speak of. He does say that he has to be careful how many "tube-driven" tracks he can stack up in a mix. But that is true with a lot of tube processors,i.e. the Avalon VT-737.Too much of a good thing, so to speak, may yield a muddy mix. Anyway, he uses it for drums, brass, guitars,etc. Kind of like having a tube version of an API 'lunchbox', if you will. Decent build quality.
As for the Midas, I work in a church that just replaced 2 Yamaha MC series boards with a pair of Venices (a 16 and a 24) in the youth ministry.We have had a Midas Heritage 3000 56-channel beast for a couple of years in our main sanctuary. What a difference from the Yammies! The mic pre's are the best I've ever heard from a "live" board-clean, gobs of headroom, transparent and open top end. So good that one of our members got his own 24 and installed it in a truck for a mobile rig, going to a Mackie HD. Great build quality.
If you need "color", go to the TLA. If you want CLEAN, go with the Venice. Either way, you won't be disapointed.

Theres a review of the M3 in a recent SOS,October or Nov., I think.