I have read a lot of good magazine articles on Rick Kuehl's products, but I am asking anyone who owns one to give me their firsthand impressions.  

Here's mine.  The nice thing about the true 22lr upper, is that the Ciener kit can be made very reliable with sub-sonic ammo.  After proper polishing of parts, I can go all day with sub-sonic match ammo.  The best thing about Ciener based units, is the 30 round mags.  

At 50 yards, I've been able to hold 1" groups regularly with Wolf Match Target ammo.  These groups have a strong 1/2" core to them, so I think I can do better.  After all, the main reason I bought this was to improve my shooting skills with equipment that isn't properly emulated with a 10/22.

Ask away if you have specific questions.

I've read nothing but good things about the Kuehl and the other semicustom .22LR AR conversion (Accuracy Speaks, Clear Lake, etc.). However, the DPMS units are also quite good and most of those of us who have them are very pleased. The custom units might be a hair better in accuracy but also seem to cost about twice as much as the DPMS (or more) after you add in the extra cost of the Ciener or M261 unit. The DPMSs are available for $400 from CheaperThanDirt.

For example, my out of the box DPMS M4 .22 will pretty much hold its own with Southern Raider's Kuehl rig shown above, using cheap Winchester Dynapoints. His will prolly beat mine by a few hundreths of an inch on paper, but I doubt that he could hit any beer can out to 150 yards or so that I couldn't!

The custom units might be a hair better in accuracy but also seem to cost about twice as much as the DPMS (or more) after you add in the extra cost of the Ciener or M261 unit.

FWIW, my unit is probably one of the more expensive Kuehl variants you'll see.  Price breakdown is as follows:

20" SS Heavy Barrel:     $250
Ciener Unit:                   $140
Upper Receiver:             $95
Free Float Tube:            $60
Charging Handle:          $15
Total:  $560

I have not included the cost of rings and scope, as that is obviously an adder on any upper.  I think Kuehl is pretty price competetive, especially with one of the lower end barrels.

His will prolly beat mine by a few hundreths of an inch on paper, but I doubt that he could hit any beer can out to 150 yards or so that I couldn't!

A challenge!  Bring it on!    Seriously, I think my upper is far better than me.  I think it is capable of sustained 0.5" groups at 50yds with the right ammo.  I'm finding rimfires to be quite tempermental in the accuracy department.

Edited to add:
Of course the guy that will spank the both of us is the one from the other thread who claims 0.5" groups at 75yds with Federal bulk pack!  

Quoted: I think my upper is far better than me.  I think it is capable of sustained 0.5" groups at 50yds with the right ammo.  I'm finding rimfires to be quite tempermental in the accuracy department.

Ah, you're catching on! There was a thread on this very topic on RFC lately, ie, how many of you have rifles (of any sort) that will shoot half-inch groups "all day long?" Turns out that damn few do. It takes a good rifle, expensive ammo, and a no-wind day to pull it off, and even then it's no guarantee.

I've found that just about any halfway decent .22 rifle can be made to shoot into an inch at 50--maybe an inch and a quarter--if you take the time to find the ammo it likes. A gun that will put every group into 3/4" @ 50 is a bit harder to find, but they're around too. The half-inch guns are rarer still, though many guns will shoot a half-inch group just often enough to keep you trying it.

You're doing quite well with your .22 AR to stay inside an inch, with the majority of shots in a half-inch. My DPMS will hold an inch, but the best genuine 5-shot 50 yard group I've fired yet ran .665, which I'm quite happy with. It is definitely accurate enough to practice my offhand or any other position with, and has been extremely reliable. I recently bench-test 17 different scoped .22 rifles and the DPMS was the most accurate autoloader. It got outshot by a couple bolt actions (one of them an Anschutz, one an old Winchester 69A), but it also outshot a couple other bolt guns!

Would love to put your gun and mine on the bench together someday, but if you're in NV you're a bit out of my neighborhood. But no big deal, we both seem to be happy with our respective guns, and isn't that really what it's all about anyway?

Yes, I've been shooting for years but never really had seriously shot rimfires.  I didn't realize that sustained MOA accuracy at 50yds with a 22lr was similar to a MOA accuracy at 500yds with a centerfire round.  I'm learning that that's the case...  

I'm still curious about the 17M2 round.  I was thinking about rechambering because my 22lr shot so "poorly".  Now that I know it's actually pretty good, I can go about my business learning how to shoot well.  This upper has done wonders for my shooting ability.  

You never know what's going to happen.  Just schedule you and the wife to take a trip to Reno/Lake Tahoe and we can put them head to head.  And yes, if you're happy, I'm happy.