It's really a matter of how you look at it. From your point of view, Samsung is having issues cause of it being on 4.2.2 and they have more kinks to work out. Granted there can always refine code to make something run better. Heck that's why project butter was started in the first place. I'm seeing it not so much as software refinement but more as the S4 is doing to much for the system to keep up. That was the reason for the overclock, Samsung knew that all the stuff they were putting on here was going to tax it. To make up for that they bumped up the processor. Did it help? on that I world say yes. Thing is HTC realized they had to do a revamp and slimmed down Sense5. With that they a very responsive user experience. If you took out all the bells and whistles that Samsung crammed into TW this time round it would be even faster.
This was a design decision that Samsung made that i'm not about to let them get a pass on. Now hopefully they can rewrite code and make it better. If 4.2.2 had been out only say 3 months ago I would say you have a stronger argument. It wasn't, and Samsung had plenty of time if there were specific issues with 4.2.2. This is all an issue of UI bloat in TW. You may not agree and that is fine. That's just what i've seen so far.
Besides, in the end there will be more goodies to come out later this year to go after.