
I liked it; it's a fascinating progenitor of the whole "Let's trace down serial killers based on miniscule clues they left!" genre, and beautifully shot. Anything filmed by Michael Mann will have some interesting stuff going on, stylistically. This film uses some interesting Conformist-esque color filter techniques to suggest different moods and hint at what's going on in the characters' heads. I also like how Mann doesn't hold the viewers' hands in terms of exposition; these characters don't need to explain the basics of their job to each other, and Mann is just going to throw you into their world.
Of course, it's not a perfect film; the final confrontation is a little on the anti-climactic side, and the soundtrack, especially, has dated pretty badly. Brian Cox's performance as Hannibal Lecter is solid, but try to remember that no one making this film had any idea that Lecter would go on to become one of the most iconic characters ever, and proportion your expectations accordingly.
EDIT: Fixed spelling