Phred:
As you know, I just got a Power Trac 1845. You're right, it is an expensive lawnmower, but I do have a lot of mowing to do, and that was my primary objective. Power Trac has developed a quick attach system that has similar function to a skid steer system. You change implements from the seat, getting off only to plug and unplug hydraulics, just like the skid steer. Power Trac offers a lot of attachments, such as FEL, snow blade, tiller and even a fence post driver. I have ordered a Long 4 in 1 bucket, and the Lackender skid steer hoe with a Power Trac quick attach. Even with those, a skid steer will surely outdig me, but I won't have to deal with three point hitches -- or picks and shovels-- at least not much. The Power Trac gives me some skid steer advantages, while still being a top grade mower.
Skid steers are also better for pure loading, fork work, etc. They generally have higher lift than the Power Trac. I started with the requirement of slope mowing, however, and the articulated Power Trac is very gentle on the turf, and very comfortable on steep slopes. I estimate mine at 20 to 30 degrees, not 45. Someday I'll get a meter, and probably find they aren't as steep as I thought.