Everything I've read (and I may be reading sources biased towards my viewpoints, so that is a problem on my part) is that the new rules improve things in every way.
That's because discussion of 5.5 is an Orwellian hellscape where up is down, bad is good, and more complicated is simplified.
I'll grant that there are improvements, but they all seem pretty much obvious improvements to make based on 10 years of experience. In many cases they are only improvements if you were playing without the Tasha's optional class rules and without common and obvious house rules. I guess if you're the type to get distracted by Malibu Stacy's new hat it all looks pretty impressive, but I would contend all the objective improvements are what a sufficiently experienced 5e player who was a moderately competent rules designer would come up with in a few days of work.
There are lots of changes to improve "balance" if you care a lot about that (I really don't it turns out), and as a result everything (be it a character option, a spell, a monster) is a lot more samey to its peers. Distinctiveness has been smoothed away in favor of endless near identical variations of class features to teleport 30 feet, and even more endless identical conjure spirit in shape of X spells. I prefer asymmetrical balance, meaning that for example at level 1 a Wizard is mostly useless in combat compared to the Fighter, but they can cast Sleep which used to be the auto-win cheat code for certain types of low-level encounters. New 5e doesn't like that sort of balance. New 5e wants to assimilate everything to working the same way so it doesn't have to playtest new things.
The system has been simplified on a theoretical level by using lots of terms-of-art keywords, plugging more features into the feat system, etc. This fundamentally makes things more complicated for people without a high level of rules mastery by requiring immediate comprehension of whole rules subsystems. A new player who has an idea for a background that isn't already covered has to digest the (no longer optional) feat system to roll up their level 1 character.
The "change things but pretend it's all the same and insist it's compatible" ethos of the edition is deeply obnoxious. When my new group I'm DMing for decided they wanted to use 2024 rules I read mostly straight through the new PHB overt the course of 2 days, and in the final stretch I came upon the (already mentioned above) spell Sleep at like 2am. And at that point I just had to pause and take a walk around the house to let off some steam. I mean, they completely mutilated one of my favorite spells with a ground-up rewrite. That I could actually forgive. What is unforgiveable is that in this and a few other instances they completely changed virtually every distinctive aspect of something, then gave it the same damned name as it had always had and buried it among a bunch of unchanged or virtually unchanged content to sow confusion. Like, just call it "Slumber" or something at that point. If you feel the need to kowtow to the people who hated Keen Mind because some player somewhere annoyed some DM, fine, remove it. But D&D does not have to have a feat called "Keen Mind", so don't write a completely different one and call it the same thing. If a Gloomstalker Ranger is going to have a new version of extra damage at level 3 no longer tied to the first round of combat during which they may have ambushed someone, don't put it under "Dread Ambusher", just make it its own damned thing. When the audience is heavily people who know 5e Classic and 90-some% of New 5e is basically the identical, hiding a few radically different things under the same old branding for no good reason is needlessly confusing and just offensive to principles of good rules design.
So no, it's not some broad improvement, except maybe if you were playing with just the 2014 core books and no house rules, and wanted a
little more crunch. For people who already have decent rules mastery of orginal recipe 5e and have already supplimented it to their tastes it is pretty much a lateral move, and one that requires buying and digesting a new set of rules too similar to be interesting but too different to just ignore the changes. And it just doesn't have all the panoply of 5e content fully converted to it yet, so why switch to a system which is only half developed? I think for many existing 5e groups the 2024 rules will remain, at most, a suppliment from which they pull ideas they like for quite a while. It's only as there is increasingly content available that doesn't plug securely into 2014 5e that 2024 6e will slowly assimilate them.