Hi, I'm a newbie to the AR platform, and I need some advice to finish my first AR pistol.  I have everything else ready except the buffer system.  The numerous buffer weight/spring options are a bit overwhelming to me, and I hope I can get some recommendations from the experienced folks here.  Here is what I'm running on my AR pistol, a 10.5" 5.56 barrel from PSA, 0.750 low profile gas block, carbine length gas system, full auto BCG.  To me, reliable function/cycle is my first and foremost concern, then obviously the lighter the recoil the better.  So, what would be the best buffer weight for this set up?  Oh, I plan shoot mostly .223 ammo if that matters at all.  From my searches on the web, I'm really interested in two compact buffer systems (I don't really like those braces, blades, or the plain long buffer tube):
1. first gen buffer assembly from gunsmoke enterprises
http://www.gunsmokeenterprises.net/product.sc?productId=3&categoryId=-1
2.maxim defense cqb pistol exc
http://www.maximdefense.com/product/maxim-cqb-pistol-exc-for-ar15-black/

Has anyone had experience with the the gunsmoke enterprises' first gen buffer assembly?  It looks like it uses its own buffer weight/spring.  Will it work well with my upper set up?
And for the maxim defense cqb pistol, it lists a bunch buffer options: standard, H1, H2, pistol caliber, silent captured spring standard, scs heavy, scs 9mm.  Which one of these would you recommend?  And what is this silent captured spring?

A specific recommendation for my current build is highly appreciated.  Also any general guideline on choosing buffer system base on various factors would also be appreciated and valued for my future builds.  Thanks in advance.

Spikes Pistol buffer spring and ST-2 buffer along with KAK tube and brace.

I have a 10.5" also and use the complete KAK brace system.  100% functional with various types of quality 556 and 223.

I start out with a H buffer and standard spring and see how the gun runs.
Each gun is different and what works for one may or may not work in another.

I run a standard carbine spring and buffer. It works. That may not for someone else. It depends on port diameter to some extent - don't know what mine is.

Many will state to use a heavier buffer and as long as pistols run larger ports than the milspec .063 then it should help to slow down the cycle speed. Bolt carriers running at the higher end tend to bounce off the extension and it's been documented in high speed photography. You don't want the action unlocking a millisecond after the primer goes off - it's a rare event but we do read of kabooms running a fast string of fire.

CRANE suggests the use of up to H3 on the CQB/MK 18 - it's left to the armorer's discretion. That should tell us that "it depends-" even they can't get uniformity from their builds and have to tune for it.

Well, I have a 10.5" barrel chambered in .223/5.56 with 0.75 low profile gas block and carbine length gas system.  Is there no way other than trial and error to find the best buffer weight?  I'm currently leaning to get the Maxim Defense cqb pistol exc.  It's $400+, so I don't think it's practical to get one with each buffer weight to try them out.  It has 7 possible buffer weight options: standard, H1, H2, pistol caliber, scs standard, scs heavy, and scs 9mm.  I'm not sure what these designations mean.  Thus I'm here seeking advice and recommendation.  If I have to get just one right now, which one should I choose?

If one owns other AR15's, I think it's helpful to have a decent complement of buffers on hand for potential diagnosis or permanent fix.  I keep a standard carbine, an H, H2, and H3 buffer on hand.  It has helped me quickly diagnose a malfunction after a new build or major modification on my AR's.

That said, I've probably gone the direction of an adjustable gas block or adjustable gas key more than buffer tweaking, but having the buffers on hand gave me a clearer idea of what was going on...or at least more confirmation that I was on the right track.  I have 9 AR's in various configurations and have used buffers and adjustable gas in different scenarios.

One thing to keep in mind on many AR's and especially pistols is that it's more the norm now to have the handguard to go past the gas block.  If you go to an adjustable gas block, this may or may not be a problem depending on the handguard and/or the adjustable block...access to the block adjustment screws being the possible issue.  This is where an adjustable gas key can be an asset, and it just may start becoming my favorite way to adjust the gas.  I was a little suspicious of them to begin with, but after using two at this point, I have found no real downside of any consequence.  Just another option to keep in mind.

Buffers, springs, adjustable gas blocks, adjustable gas keys, drilling gas ports, and on and on...they can all work and some are better than others for a specific situation and conditions.  Some get downright religious about these choices, but in reality there is probably no one absolute.

In the middle of a build right now myself.  Researched around for quality & price point and came up with the Phase 5 Pistol Buffer Tube Kit.
Time on the range will be the final factor.

I'm new to the AR platform as well, but I'm thinking that if reliability is your first priority you might want to stay away from the ultra short buffer systems. Most of them use proprietary parts and will not be as flexible as a standard length buffer system, dedicated parts and all.

That said, I also wanted a compact pistol and went with the MBV micro pistol buffer kit and am quite happy with it. I realize though, it has its limitations.

The AR pistol I have is a 7.5" barrel and I am using the standard carbine spring along with an "H" (heavy) buffer.  Not had any problems and has digested several different loads with no problems.  I also am using the BCM extractor spring kit with a heavy spring, black rubber bumper and o-ring.  Have not had any problems with that either, am using it to make sure the extractor doesn't jump the rim.  I believe on these short barrel/gas system pistols there is a little more violence on extraction and ejection.