I do it too!
(All of us early risers for the 7:00 a.m. MM are coming out of the woodwork!
) I love the early MM's - what a great time to really see the wonderful details of Fantasyland and walk through the area while not getting stuck in crowds. Granted, I may not use every MM I have if I am staying onsite but I will at least use one MM and try for 2 if I can.
I've done Saturday and Sunday MM's. I always go during the holiday season, which is extremely popular. In addition to the huge benefit of being able to do the Fantasyland rides with next to no wait, if you can get on IASW Holiday during an MM that is an excellent bonus because that line gets looooooong as the day progresses. My friend and I were lucky to get on IASW Holiday during MM - once at the beginning of the MM hour, just after 7 a.m., and once at the end of the MM hour, because IASW Holiday opened a bit late. Both times we sailed right through the queue and onto the ride and there were all sorts of empty boats around us.
I tried to convince my friends who are supposed to be in town later this year that they should do at least one MM to get their son on the key FL rides (he's never been to DLR before) because it will be extremely helpful, but they don't think they will be able to make a 7 a.m. MM - they just can't get up and out early enough to do it. It's definitely not for everyone - some people just have families that cannot make it up and out that early. And some folks don't want to have to push themselves to get out that early. But if you happen to lean towards being an early riser anyway, definitely try a 7 a.m. MM!
In fact,
sometimes, if I'm not mistaken, if DL has to close early during a busy season like the holidays (maybe it's some special private after hours event that is out of the ordinary for the season), they have actually opened the park an hour earlier than they normally would to allow people to get extra time - at 7 a.m. - and then the MM would be at 6 a.m.!! This happened on a couple of days last year in December. If I had access to a 6 a.m. MM, I would be doing that too!
I always figure that since the Saturday morning MM starts at 7am it's the best option on two fronts. (1) because the way I see it fewer people will have the motivation to get up and it wont be as busy as say a MM on a Thursday - and in my experience I saw far, far, far more people at the gates for a Thursday MM than I did on the Satuday MM that I went to - and (2) because Saturday is a busier day in general so why not take advantage of that hour so you can get seemingly get a lot in on a busy day. I always make sure I do my MM's that way, mind you I'm not travelling with kids, but I would still try my best to make it happen.
I wanted to leave around 1am but they liked the idea of staying up that late and hitting the rides. We did nap. They were 8 and 6 at the time. Then they got up at 8 and were raring to go. Geesh I was hoping to sleep in. 
