Wow, Lots of angry words about Salient.
First off - I own a couple.
And Secondly, yes, I drink Cool-Aid sometimes.
Lastly, they're F-ing Great guns.
I have 3 currently - Tier 2 34, Tier 3 w/T1 internals 21, Custom (no package) 32
I have spent a few hours with these guys, and found them to be good folks. I can't speak to any issues pertaining to their business practices, but my experience with them has been positive. The work they do on pistols (Glocks and M&P in particular), is pretty impressive. I came from the viewpoint that a John Browning based handgun was the only thing worth customizing (1911 & Hi-Powers), but I've changed my position on that after spending time with these guns.
There is much debate about the cosmetic aspect of the gun - but this isn't what changes the shooting experience. The internal work is where the most improvements are noticed. I was there with the owner while he installed my trigger and it took almost 2 hours as we went back and forth to get the exact feel that I wanted. The trigger is the best I've ever felt on any glock, period. I've tried the ZEV, I've tried other "Custom" trigger jobs, etc - nothing gets close to this trigger.
They hand fit the match grade barrels, they do impeccable stipple work and grip reduction - Some people consider this Cosmetic, but my 21 feels like an entirely different gun after the grip reduction, very comfortable even in my medium sized hands.
The slide work does look nice, don't get me wrong - but it is also based on performance - by removing weight you reduce felt recoil and improve time on target. This is something you can feel if you shoot a lot - if you're a casual shooter you may not see a difference in anything but the aesthetic. I'm not a pistol comp shooter and personally felt that the Tier 2 & 3 packages were better suited to my level of shooting, but I know a few guys who are at that level and say the work makes a difference.
I've had several Custom 1911 builds done as well as Hi-Powers - and while those are definitely more romantic than a custom glock - If the Shit hit the Fan, I'd take a Salient Glock with me. They still retain the reliability of the glock, along with hi-cap reliable, dependable mags. 1911s are finicky and generally undependable, they require a great deal of maintenance and upkeep, Glocks are the workhorse of the pistol world - Salient simply makes them easier to work with.