Is it a better idea to use a Ciener conversion kit or go straight to a .22LR upper?  I saw an older Ciener kit today.  Has Ciener changed its design over the years?  Are the current one better than the old ones, say, from 5 yrs ago?

You can do both.

Keuhl will use your Ceiner to make an upper, as well as do any polish work on the unit to optimize it for their kit.

Ceiner is a good product, but it may have teething pains.  Mine worked for the first magazine or two and then developed a nasty tendency to stovepipe.  The feed lips must be to spec, and all burrs and rough spots on the extractor and feed ramp must be taken care of for it to work reliably.

I used info from the following sites to take care of the problems I've had:

Triple break Ceiner fixes

Fun Supply Ceiner fixes

Hope this helps,

Michael

I'll recommend the Kuehl or other true 22lr upper.

One of the fundamental problems with the Ciener is that it uses a smoothbore chamber adapter for an oversized barrel.  This prevents a good gas seal, and thus he does not guarantee his units will work will anything but high velocity ammo.  Accuracy may be another issue, which I won't address here.

A true 22lr barrel improves the seal, and with a little polishing of the unit, sub-sonic operation is not an issue.

If you have an old 1:12 barrel, you might be able to get acceptable accuracy out of the conversion unit. My opinion is that trying to "convert" a 1:9 or faster barrel is an exercise in disappointment. You'll be much happier stepping right up to either the CZ or DPMS uppers.