I think some of it is subjective, some of it is down to layout, some of it is down to seat design, and some of it is probably down to how Taron is running on any given day.
I've been to Phantasialand twice. The first time, Taron was comfortable enough, but not really showing it's true potential. The second time, it was far faster and more forceful, and that's when I started to have issues with it.
Insane laterals either during airtime hills or if you accidentally lean a bit too far during a sharply banked corner seem to be an Intamin thing - most other manufacturers don't seem to push things to the same extent. Mack have built some very similar elements, but theirs tend to flow a little more smoothly and be a little less forceful at the same time. Some of the issue is probably layout/trackwork, but I realised when riding that train design is also partly responsible. Take a look at the design of the Mack train:
https://rcdb.com/14312.htm#p=90713
Note the design of the seat - it's like a deep bucket, far enough out of the way to be unnoticeable when riding, but it wraps around enough to provide upper body support when needed. It's effective, but you don't even notice it's there.
Now check out the Intamin trains from Taron:
https://rcdb.com/12723.htm#p=71484
Note that the seat back is much narrower. It can't support you when the ride throws you to the side (and it will, by design). It's got a subtle curve to it, which actually makes the problem worse - when you get thrown sideways, the edge of the seat actually scrapes across your back, so you've got that to contend with as your back muscles work overtime trying to get you back upright and the train tries to pull you sideways.
After a lot of rides on Icon this year, I was actually quite surprised as to how much this bugged me when I re-rode Taron. Last year, I initially thought Intamin had managed to match Mack for rider comfort, and they certainly have in terms of restraint design - having had major issues with their old restraints, particularly on iSpeed, the new Intamin lap bar is absolutely spot on. It just feels like Intamin went a little OTT in a couple of places, and forgot about rider comfort in the process. It's easily fixed, either with some subtle changes to the track profiling, some subtle tweaks to the design of the train, or a combination of both.
Don't get me wrong, I adore a properly designed, intense Intamin. Their best coasters are legendary for good reason. I'm not looking for reduced intensity, just a bit of refinement to make it more comfortable in the process. I suppose I view Taron as a very successful mark 1 prototype, and it was good, if imperfect. Now they're building a mark 2 follow up, and I really hope they're aware of what I consider flaws in their first effort, and take action to resolve them, rather than doubling down and having the same issues with all of their subsequent rides.