thinking about picking up a frameset and building it into a hybred cross/commuter type bike. Do any of you ahve any thoughts or opinions about these bikes or this plan?

Yeah, I have an opinion. I think you should post this over in the commuting forum.

'cept it's a mountianbike. Not every "mountian" bike gets ridden down a mountian y'know.

'cept this is a Mountain Biking forum, which means that discussions generally revolve around mountain biking.

If you're looking for insights on how a particular MTB frame can be repurposed for something other than mountain biking, you may be better served elsewhere. Just saying.

I rode an M500 for about 6 years as an off road bike and I had issues with going over the bars on a pretty regular basis due to the frame geometry so I upgraded to a Gunnar Rockhound with a longer toptube, not to mention the steel frame which is more suitable to my style of riding. IMO the M series C-dales would probably be better cross/hybrid/commuters than MTB's.

Turns out the frame in question is an M500. Right now it;s sitting in the back of the garage. I bought a Ross Bryce Canyon to strip for parts and couldn't bring myself to do it. It looks nice. I had to sent the wheel out for truing so I ahve only riddden it aorund the block but I really liked it. So, then I went out and bought a beet 15.5 inch Trek 4300, also for parts. It's a whole diferent style MTB than the other (four) ones (sort of like an overgrown BMX bike with gears) so I am going to rebuild THAT instead of stripping it! THey are all entry level or mid range bikes I gues, but they are nice enough for what I'll be using them for. Looks like the cross project is on hold for a while.

I have the M700 mtn bike. I've run 1.0, 1.25, 1.50, and 2.0 slicks on it for commuting and blasting around town. Currently using the 2.0's as they have a little softer ride and the Cannondale does not flex for anything. I have an old Ritchey that has thousands of commuting miles, minimum 30 miles round trip. What I like about the big tires on the mtn bike is being able to take detours without worry of flats and just bombing through everything. My newest bike and commuter is the Redline Monocog 29er. Wife was a little peeved when she saw it. First mod was install some Bontrager 70x35 Select K's. Need to gear it up a bit and get the bars lowered. Best part of commuting is taking the long way home and letting the day's crap float away.
You can do it!