I would suggest a radial arm saw. I know, I just caused you all to suck the air out of your rooms, i.e. Big Gasp. But, I've worked as a trim carpenter, and specifically as the saw man. I cut wood eight hours a day, six days a week for years; no SCMS was ever able to retain the accuracy of a good set up and I was never able to achieve a really accurate setup. I had to check and reset the stops every week.
When I worked in a furniture shop, we used the radial arm saw for cutting the ends of rough sawn boards, and extremely accurate cuts using jigs (the saw was always set to 90 degrees and woe unto him who moved it from there). The point being: it was rock solid but infinitely adjustable, getting it set dead accurate was easy but not easily repeatable, and using jigs for angled cuts gave us infinite adjustablity while maintaining accuracy. Plus, a radial arm saw has a bigger work surface, a deeper cut and a longer reach; Meaning you can crosscut that 3" thick 20" wide mahogany slab you've been saving for years.
An early Rockwell or early Dewalt would be a good choice. They can be found relatively cheap and generally all you'll have to do to get it in tip top shape is clean it up and, worst case, replace the bearings. If you use a lot of thick stock, look for a 14 or 16 inch saw. The blade will be expensive, but it will last forever. Also look for one with an electric brake: in a good saw with no electric brake, the blade can spin for 20 minutes after stopping the cut.
As to safety, radial arm saws ARE safe if operated properly. I certainly wouldn't use it to rip boards if I had a table saw, nor would I use it to mould edges if I have router or shaper. Put a good blade (made for radial arm saws) on it and always be aware of your hands. These same rules apply to the SCMS.
SCMSs are great for mobility, and if you choose to go that route, I'd suggest a 10" slider. Recent magazine tests suggest Milwaukee and Bosch. The ten incher is less expensive and will do anything but the tallest mouldings, if you learn to cut crown flat (which is much more accurate and easier than bedding it at 45 degrees to make a cut). Ten inch blades are also cheaper and if you want accurate cuts you'd best plan on spending at least $50-100 to replace the stock blade.
In summary:
The radial arm saw is IMHO more accurate, more versatile, and as rock steady as it gets.
The SCMS is portable.
There you go, the dissenting arguement.
James Ray