I'm not sure if you are asking about current or past offerings. If you can find them on the secondary market, those Umarex - Beretta FS92 and Umarex Colt 1911 .177 CO2 pistols are fantastic, from a weight, accuracy and all around fun plinking perspective. Probably about 15 years old since they came out.
Not sure if you are looking at a repeater or single shot. The old Crosman 2240s have also been fun guns. Same for the Benjamin EB22. Both are single shots. I have seen those on the secondary market
I bought an X-Five CO2 pistol years ago and the quality was not as good as offerings from the past. Also, the selection seems to have been better in the past before the government seemingly put the kibosh on a lot of new models due to what they perceive to be CO2 replicas of "real" or authentic cousins.
The only CO2 pistol which I disliked immensely in my life was the Crosman T4. I should have known that anything that shoots BBs and pellets interchangeably is probably not known for accuracy. There thing was a jam-o-matic.