[creed_DET5]

Look at what's being used in the field.  For police duty carry, the SLS belt holsters are probably the most popular ones out there.  They're fast, and they're secure.  The drop-leg versions of the SLS holster are quite popular with specialty units, both in law-enforcement and the military.  For those applications they offer the additional advantage that they can be easily painted to blend in with BDUs, or even purchased in several of the more popular patterns.  If you're going to be doing a lot of transitioning from your primary to your sidearm, that's what I'd reccomend.  You pay a lot for them, but you get a fine piece of equipment for the money.
If you don't like thigh rigs, or don't anticipate using your sidearm that often, a double .223 mag pouch can be converted into a holster for a large-frame automatic without too much trouble.  The mag pouch under the weak-side arm on most six-pocket tac vests (the ones with six double .223 pouches across the front) is a good candidate for this mod, since it's also the pocket that it's hardest to get to with your weak-side arm.  Blackhawk even makes a combination pouch with a thumb snap under the cover flap for modular tac vests.  I had one a while back, and it worked pretty well.

-Chris

[azsarge]

For mounted (riding in a vehicle) ops, torso or chest moounted gats are the way to go.  

When dismounted, it's whatever works for you!  I like the conveneince of the subload, but sometimes opt for the rig-mounted holster.  Transition is only crucial when in close combat, and most of our airsoft games take place in the field where a secondary is used only for backup (or for the sake of using a pistol).

Safarilands SLS hood is tops in my book.  From what I've seen around post, everyone from MPs to deploying Generals choose the Safariland setup.  Some dislike the shroud, and opt for the 6280 or 6281, but the holster is chosen by nearly 100% of those who know the difference.

When I see a guy wearing a thumb-snap closure rig on his leg, I just assume he hasn't heard of the SLS. ha ha

[Raven1]

I know you have a springer now but Ultor hit the nail on the head!  Bottom Line, you want to spend money on a holster that going to keep that burner where it belongs! Right at your side and ready for use when you need it!  

Nothing worse than spending all that cheese and losing that sweet piece at some large Op like Lion Claws! And The Last thing you want to do is spend half your time looking for lost gear.  Or worse having to finally leave back at camp because your side arm keeps falling out every 12 steps!  Ha, I Love Watching That, It Never Gets Old!

If you read the replies to you questions, besides the excellent input, the other commonality is people are using what works for them / with their kit!  Sometimes it takes a lot of variations, a lot of experimenting and sadly a lot of money!  Welcome to the "Big Boy" sport kid and your new addiction!