The trigger pull is interesting. It does not compare well to the trigger pull of a quality SA auto like a 1911 or a BHP. If you expect it to do so, you will be disappointed. What it does do is compare very well to the duty triggers present on most polymer pistols (Glock's SAS, for instance...where the striker is partially cocked by the slide and finished off by the trigger pull) and polymer or steel DAO handguns. That is, naturally, a subjective measure, so people will disagree about which is "better", but it certainly is in the same league. Personally, I think it beats the pants off of the rest of them.
By "interesting" I mean that it is not clean...you can feel some "stuff" going on as you pull it back, but it is by no means bad. It is predictable and you can stage it easily (but it is light enough that you don't really have to do so). The reset took some adjustment for me, but I'm used to the 4506's DA/SA. After a few trials you can work it pretty well. For a duty gun, it is a very good trigger.
As far as length of pull and weight, it is somehwere between a DA and a SA. It is long enough and weighty enough that it is safe without an external safety, but nothing like a traditional DA pull on a DA/SA, or a DAO variant of a DA/SA pistol. Like the Glock, the action is partially cocked by the slide, and the trigger pull just takes it the rest of the way. There's no real way to tell how much of an influence the mag disconnect has on the feel of the trigger without shooting one so-equipped side-by-side with one without the disconnect. I've only shot ones with the disconnect, and I'm perfectly happy with the feel of the trigger.
The gun really shines in the ergonomics department, which is something I never thought I'd say about a S&W autopistol. You have to hold it and shoot it to appreciate this. Such things are entirely subjective, but the only gun I've shot with better hand-feel is my BHP. It's that good (to me).
It's by no means perfect, but it's a pretty good gun.
Mike