Justin-
I don't think the Tactical Solutions rimfire upper, specifically, has been out for long. However, utterly similar products from other vendors (Spikes, Model 1, et al.) have been. AFAIK they all use the same modified Ciener bolt and a barrel with a .22LR chamber and no gas port, with the last 1/2" or so of the barrel turned down to fit into the bolt assembly.
In addition to a dizzying variety of complete rimfire uppers, Model 1 Sales sells the parts to roll your own, so I'm using their site for these pictures. But again AFAIK, all the vendors build something similar.
The barrel assembly looks like this (yes, headspace is kinda funky, but it works):
The bolt looks like this (slides in and out just like a "real" AR bolt ass'y):
I use mine (a Model 1 16" HB carbine with an A2 upper and A2 sights, on one of my regular lowers) for paper target practice at 100 yards. Works great. I've contemplated getting a scoped fluted bull barrel version, too, but need to save money for now.
Why I would get the dedicated upper:
1. The extra volume of the AR upper receiver allows for a LONG time between cleanings, since it would take a LOT of fouling to interfere with the operation of the thing. This is a good thing, since it's easy to go through a brick in no time flat. A drop or two of CLP to lube the bolt, and I just keep shooting. And shooting. There's lots of fouling, but it matters none. If you want to clean it at the range, it's easy, but if you just want to feed it brick after brick and pass it around to your friends, it works fine too.
2. I have successfully used the cheapest crap ammo I can buy from Wal-Mart. Lead, copper, "Golden Bullet" bulk packs. And I've used the good stuff. Accuracy varies, of course, but feeding is no problem either way. Works flawlessly with any of it, as long as I add a few drops of CLP from my range bag bottle when it gets dry. I sure as hell have never seen a 10/22 do that.
3. I'm guessing you have a few extra bucks in your lower parts and stock.
You can leverage the investment with the .22, and the trigger will feel the same. All the controls are the same, so it's a true .22 trainer.
4. The magazine is IMHO far superior to the Ruger's. (I have the park'ed steel Ciener mag above, not the Black Dog.) The spring tension is very low, the thing is 100% reliable, and loading it is quite pleasant. My experience with Ruger mags is that reliability can be spotty and loading is a PITA after a while. Yes, you can get a loading tool for the Ruger. But I don't feel like I
need one for the Ciener mag.
5. Cleaning is night and day better than with the Ruger. Cleaning the .22LR upper is like cleaning an AR without the gas tube. It's REALLY easy, you need
no tools, there are no springs to wrestle with. Cleaning the magazine is like cleaning a skinny AR mag. Again, there's nothing to wrestle and you need no tools. Like an AR, you can easily clean the gun at the range if you want to.
There's only one complaint I have: no LSHO. That's it. ZERO other complaints from me.
I've had mine for a while now, have thousands of rounds through it, and I love it. If anything, the TS version may have a nicer upper receiver than mine. Mine has tool marks inside it. This has not had any impact on its performance, though, and at $475 complete and a one-week turnaround, I'm not complaining about the Model 1. If the Model 1 works and shoots well, the TS should be at least as good and maybe better.