Depends on personal tastes. I worked at used car lot around 00-01' and we had quite a few of those Caddy's on lot along with Sevilles. I was allowed to use a couple of them for parts running or grabbing titles, etc. At 70k miles, had one seize a water pump on the highway (Northstar variant). But other than that, I think they are nice enough. 300hp really doesn't feel like it though, given the 2 ton heft. Also, that period of GM trans needs religious fluid changes. If it even smells slightly noxious, pass on it. Also, those cars were FWD.
The Town Car will probably be easier to work on. They were RWD. Same deal on trans fluid, shouldn't wreak like a bad hair perm if you were around when those were fashionable. A noxious chemical used to treat hair. Trans with bad fluid will get noxious, and loose the pinkish red coloring if on a white paper towel. If around 100k, expect issues with front wheel bearings, ball joints, etc. i.e. they'll need replaced at some point.
Either car, will most likely need routine stuff done (especially if neglected) to make it happy for daily driving. If possible, get a warranty. If buying from a private seller, do your due diligence with finding out that year's quirks, and recognizing right off the bat what the car might need.
The Town Car will give you WAY more trouble free miles just make sure its had the intake manifold changed or its an 01 and later. Either way the Lincoln will run longer with fewer repairs, the Cadillac will be quicker.