The Caddy Northstar V8 is a device to deliver oil to the ground first and an engine second.
That said, it's got good power.
I prefer Lincoln's offerings as the Ford 4.6, while delivering only ~210 horse in the Town Cars (91-97, 190 in single exhaust models), is easy to work on and will last as long as any engine on the road.
In addition, the Town Car is rear-drive, and as a personal thing I love the way the '90-'97 body style looks.
I own a 1997 Town Car Cartier, I love it, it's smooth as hell, handles well enough for anything I'll ever need to use it for, will eat interstate miles like nothing, has lots of toys for a car of it's age and price, and hold buckets of people and stuff.
If you've got specific questions about it, ask.
You've got to be a bit careful buying these years, though. You'll want one that has had the rear air bags (suspension) recently replaced (or with a price low enough you can do it/have it done). You want a '96 or a '97 Cartier. The older models had the AODE Transmission instead of the 4R70W (I think the '96 had the 4R70W. I know the '97 does). The transmissions are very similiar, but the 4R70W will last significantly longer (provided it's been taken care of).
Aside from the rear airbags and the transmissions in earlier models, the car is rock solid. Keeping them 100% generally just involves cleaning sensors and the like periodically.