I find slurs all over the place in the music I play. Yes, the trombone has the potential to achieve that very cello-like legato phrasing that other instruments simply can't. However, the nature of the trombone being what it is, ther potential is also there for sloppy playing due much to poor slide technique.
One of my biggest pet peeves is when players over use it and slur notes that should be tongued. I was playing a gig yesterday doing a lot of marches, and some cats were sluring notes all over the place??!?!?! It was driving me crazy. I guess I'm just saying yes, work on a good sluring/legato technique, but also know when it's appropriate.

I really took to legato tounging since it was taught to me. What people miss is that when you get a trombone slurring on some slow stuff you still need to have a fast slide, thats the sloppiness somebody mentioned. The gliss is also mad fun but that almost never shows up.

Lol I think its funny watching !****!s do the slurs on completely out of the way notes when their note supposed to. Bb and high Bb are in the same postion so why do they move it lol..

Not necessarily.
On my large tenor, the high Bb has to be kicked out some to be in tune, so it plays farther out than the Bb and octave below it.
On my small tenor, it's virtually the opposite.
Fact of the matter is, the "correct" position for a note is where it is in tune.