(a) I've had the thing for 35yrs and (b) out of the box it (still) shoots 1" groups at 100yds.
I wouldn't
touch it. I'd keep it in a humidity-controlled safe, with padding all around it in case it slips off the racks. I'd be VERY careful when cleaning it, and I wouldn't take it to the range in anything less than an airline-approved hard case.
You could spend $500 on modifications, and it probably would shoot a tad
worse when you were done.
Seriously.
A 10/22 out of the box is not especially accurate. But a few hundred bucks and you have a tack driver.
And when you've spent your $500-600, you might just think, "Wow, for this money I could have bought a really
nice rifle..."
That's what I did. I bought a 10/22 once. I shot it a few times. I
tried to get the !@#$ magazines to work well, put a scope on it to see what accuracy it was really good for. Then I sold the POS and put the money towards a really nice .22 rifle. If you're going to spend $500 on a .22 fun rifle, IMO consider doing yourself a favor and get something like a Marlin 39 lever gun with the cash. More fun than the semiauto, reliable and accurate, too.
Between the two guns in the OP, there's no choice in my mind: get the CZ.
Now Ruger's .22
pistols, on the other hand, are wonderful guns right out of the box. After getting one on sale and shooting it, I bought another, which is my scoped match gun with
minimal modifications, and both are utterly reliable. And whenever I see one in the store, I have the urge to buy it, too. All those barrel lengths, two grip styles, collect them all!
Fortunately, I can control myself, so I can still afford to eat and pay the mortgage.