I've got an M-zero. Does everything I want of it. I don't commute but do mostly use it for utility cycling in traffic - shopping, errands and the like. It comes with braze-ons (mounting points for mudguards and racks) so would happily commute.
I use mine weekends as well on a local disused rail track, some of it it paved, some isn't but a few muddy puddles and gravel tack don't present any problem. I have fitted semi-slick tyres for a little more grip on the track during the winter (and last summer!) than the Escape came with, but they do effect speed / handling on road slightly.
If you are going for mudguards, rack etc.I believe you can get them on the bike under cyclescheme when you buy it, so saving a few extra quid. Possibly clothing as well if you need it- would be best to check with Dales. A decent cycling specific jacket can be a few quid, but worth it.
What sort of commute will it be? If you intend using it mostly on road there is also a more road orientated version now than when I bought mine, the Escape 'R' range which comes with larger 700c wheels, should be faster on-road, and you WILL want to catch and overtake that guy you see every morning on the way to work
or beat the bus.
If any off-road bits, or a prospective weekend use like mine the 26" wheel version may be better.
For your commute the Escape should serve you well. I find the disc brakes superb, very powerful in all weathers. Others here will no doubt champion their own favourites.
The real commuters can advise better but I'd say build up you time on the bike commuting, not cycling everyday at first, or only cycle one way if you have somewhere secure to leave it and back the following day.
Don't forget to budget for lights and decent locks. I'd advise 2 (cyclescheme?).
Most importantly remember the "really enjoying it" bit