I had a '95 Buick LeSabre with the 3800, it was a great car overall.
Road handling/etc are exactly what you'd expect, it's a boat.
Comfort/reliability are outstanding. Original motor/tranny were still going strong well over 200k, and sold it still running. Only replaced suspension bits, starter, some ignition thing in the steering wheel (receptor for security key dealie).
Fuel economy in town = meh to poor depending on driving habits.
Fuel economy on hwy = good to excellent (I regularly saw 30+ using 89 doing constant 70).
All that said, I think the Focus would make a better choice if you're doing more than 50% of your driving in town.
If you do get a Focus, make sure it has the Duratec motor, it's in all '05+, and in some '04 models. It's a significant improvement over the older Zetec and especially the SPI motors in older Foci. No timing belt to fuss about, and the best fuel economy and power of the Focus motors (the SVT had 170hp instead of the 130hp regular Zetec, but it was pretty high strung, the Dura 2.0 can be built to 200+hp NA, but in my mind it's almost idiotic to worry about, stock is fine for a DD).
I have a 2.0L with the 5-speed, and I average over 30mpg driving mostly city, and sometimes like a bit of a hoon. On long trips I average 40+, even with AC, luggage, etc.