I have a 1D M2, a 7D, and a 5DM2, so I can speak from some real world experience. The 1DM2 was an awesome camera for its day, but that day has passed. Its advantages over the 7D are:
1) Better build - stronger, better seals. It feels like a rock (and weighs as much).
2) Larger sensor - that gives you slightly less DOF than the 7D at any given lens/aperture. The downside is that you can't use EF-s lenses on it, so it is hard to get very wide with it.
3) Better controls - It has a wicked efficient control layout...if you take the time to learn it and use it a lot. If you don't, it is wicked complicated and hard to understand.
4) Better AF - The 7D (and I'm guessing the 60D, but I don't know), has a really good AF system. The 1DM2's is better. Both are great, so the difference is pretty slight. Both make the 5DM2 seem pathetic.
5) Built in portrait grip. I like the feel of a built in grip more than the add-on, but it is really nice to be able to take it off, which you can't do with the 1D. It's a big camera whether you like it or not.
It might have a slight noise advantage, but not by much if at all.
It has a few other advantages like 9 shot bracketing. I'm sure I'm forgetting a few other things.
It has major disadvantages relative to the 60D. The LCD is tiny. No LiveView. No video. Antiquated menu system. No in-camera flash menu. No on-camera master flash. It has a much lower resolution (8mp). It uses huge NIMH batteries that won't hold a charge for long in storage. They are big and heavy, so you won't want to carry a spare. It also uses a different charger, so you'll need to take two if you travel.
If you plan on a rugged, outdoors trip where reliability and durability are paramount, I'd get the 1D. If you need the absolute best AF you can get, I'd get the 1D. In just about every other set of circumstances, you'd probably be better off picking up a t3i or a second 60D.
My 1DM2 sits in a drawer and hasn't been taken out in a long time. I suppose that I should sell it. I used to think that I'd use it for nasty conditions like beach outings, but I never do. It was a great camera that blew away everything else in its day in the things that mattered to me. That was a long time ago.