Thank you for the detailed and helpful response. I will look into the CZ 457. It seems like everyone is partial to the T1X. I need to put my hands on a couple of these. A question: what is the Ruger RPRf? A variant of the RPR?
You'll get a LOT more info by looking at the sticky threads for the T1X and the 457.
As I said, your choice may come down to personal preference - not to mention availability. While I'm a big fan of Tikka barreled actions, I detest their plastic stocks. Does that mean the plastic stocks are objectively bad? Well, I guess it depends, as someone noted earlier in the thread, on your definition of "precision." The plastic stocks are feather-light and probably nice to carry around hunting, but there's little or nothing "precision" about them. You could certainly start with the plain T1X and put it in an aftermarket stock or chassis as you learn and the addiction takes hold (maybe it won't!). You may be perfectly satisfied with it out of the box - try it and see. I'm a chassis snob; other people like more traditional-profile stocks. If you're one of the latter, the "stock stock" may well not be as icky to you as it is to me.
I'm basing my opinion of the CZ-457 on the two I've actually
seen perform on the range coupled with my experience owning a 455. I have not actually shot one. The 457 is rather different from its predecessor 455 - different footprint (a 457 will not mount in a 455 stock or chassis), 60-degree instead of 90-degree bolt, and I think the trigger on the 457 is adjustable (but will still be heavier than many prefer).
I've shot one T1X and haven't seen any others on the range. Honestly, the guy who owned it struggled with it. It would print nice groups with mid-grade match ammo brands for about 35-50 rounds after cleaning, then the thing would seem to foul and groups would degrade. I honestly cannot say if the issue was his particular copy of the rifle or a user-induced problem like over-tightening the stock bolts.
The RPRf is the Ruger Precision Rimfire; some abbreviate it as RPRR (Ruger Precision Rimfire Rifle). There's a sticky thread on this rifle as well. It arrived on the rimfire scene riding a lot of hope and expectation that it would perform as well as its big-brother RPR (Ruger Precision Rifle) as an entry-level precision product. In short, it's been a disappointment. I shot my nephew's quite a bit. Compared with the .22s I grew up with, it did fine. Compared with its current competition... not so good. Again, depends on your definition of "precision."
Another new guy question, what barrel length is best? I am seeing 16 - 24" in the CZ and Tikka.
16-20 inches is plenty. The longer barrels - at least in the CZs; I haven't paid any attention to Ruger - are configured with iron sights where the additional sight-plane length aids accuracy, and are mounted in a stock whose drop-at-comb is intended for irons - e.g., way too low for a scope without adding a cheek riser.
There's a wealth of information here in the SH rimfire forum. You'll next be looking at optics. Do a lot of reading here, and don't rush. You're looking at decent rifles, so it's to your benefit to equip it with a decent optic. Think Athlon Midas-TAC, Vortex Viper PST or similar. Again, read a lot before spending.
Hope this helps.