The Hunter 22 is much different than a Hunter 23 or a Hunter 23.5. The first one is a cored hull and I once saw an impression in the hull skin from the slings used to pick the boat to do a bottom job. So, the outer skin is pretty thin, I would say. Of the 3 the H-22 has the most interior space. The Hunter 23 is not what I would call a "fast" boat in comparison to "fast" boats (like a J/22, Lindenberg 22, Merit 22, Santana 21, San Juan 21, Pocket Rocket 22, yadayada), but probably the average Hunter 23 sailer never sailed a really fast boat. Winged keels are not fast to weather - period. Anything that gets deeper into the water helps windward performance, so, from that perspective the Catalina 22 might be able to point higher with the swing keel model, but that keel (cast iron) is not what I would call a NASA shape either, so it is not as efficient as it could be. The Catalina 22 has been built since the 60's and the latter models had the same hull shape and sail plan as the earlier models so that they would comply with one design rules. But, later they changed the keel shapes (winged) and so that destroyed any continuity in the one design rules anyway. Earlier Catalinas had Nicro Pressed rigging while Hunter always went with swaging, but Catalinas of the same vintage of the Hunter 23 also had swaged fittings. The backstay on the Hunter had a bolt the size of no more than a 1/4" to support the backstay chainplates and I thought that was a bit light, but at least it had a backstay unlike many modern Hunters.
But, the endorsements of the various Hunter owners and Catalina owners show their pleasure as boat owners and they are happy with their boats and that is the main thing.
The argument about parts.....I know Catalina is great for supporting their older boat customers and parts are available way back into the years. Not sure about Hunter - not as much experience with them. And, as mentioned, a lot of parts are not provided by the boat manufacturer, such as winches, stoves, lights, etc. But, Catalina does make their own masts, own turnbuckles, unlike Hunter and that way they can keep the price down instead of sourcing from mast manufacturers, hardware manufacturers, etc.