As I was reading his descriptions, I found some of them a bit surprising but I think more in the choice of words compared to my own experience. I intended to follow up on them, but I'll do it in the context of your comment above. Might be interesting as I wondered if he simply chose words I would interpret differently than he does or if, perhaps, in some cases he is doing something that isn't necessary. So, let's get to it:
This was a big one to me because, at least in my normal usage, I don't see any noticeable delay. My usage would normally only involved adding the space bar to access the green layer and I just zip right along. As I've mentioned before, I did have a problem with how long I tended to hold it down in certain situations, leading it to give a green layer instead of a space. But WT added filters that you can set faster or slower. That pretty much took care of that. But, in any case, the problem was that I tended to hold it down MUCH longer than the typical person (measured in micro-seconds or something). It is much faster than using the shift key as a modifier on any keyboard since the space bar is so conveniently placed in comparison.
So, my first question to petek would be, are you deliberately slowing down when accessing the green layer? Because you shouldn't have to. Depending on what he's doing, he might want to look at the filter.
Then I thought that maybe he was referring to the other chords. That gets a bit harder for me to judge because, while I certainly use the command chord or command hot corner, they are almost always in isolation. That is, not something I'm doing as part of a fast typing routine. Maybe petek is different. But it may also be that he is misinterpreting something. When you hit a chord, certain LEDs light up based on the chord. Perhaps he is waiting to hit the next key until after he sees those light up. But you don't have to. I just did some tiny testing, hitting the command chord, alt chord, and command hot corner with another key as fast as I could. Worked fine even though I was done before the lights would show up. Of course, these are just possibilities. I'm really interested in clarifying his experience.
I have no idea if large hands make it more difficult, but pretty much all of us have reported the issue of getting Enter instead of apostrophe. For me it was worse since I use Dvorak so it would be the far more common "s". Also had a problem with delete and P (L on Dvorak). While I recommend people don't change boundaries until they adjust to the TB for awhile, I do make an exception for those two pairs because they can be quite annoying. So I set the boundary on the apostrophe/enter pair to extremely bias in favor of apostrophe. Which made the vast majority of these errors go away quickly. So I'd like to know if petek has done this.
True. But I'd add that most are changed in a very logical way. Best example would be all the symbols you normally see on the number keys accessed with shift on a regular keyboard. Normally they are on the 4th row from the bottom of the keyboard - or two rows above the home row. Thus hard to reach and takes a LOT of practice to hit without missing when reaching. But on the TB, every one of those is on the home row itself, accessed simply by hitting the space bar too. Amazingly easy and since the order is the same, not hard to remember at all. I no longer have to look down for those characters. But, yeah, there are some rarer used ones (for most people) that have to be relearned. Of course, if a rare one happens to be common for you, you can always customize it.
I wouldn't call it fragile, but yep, you don't want dirt to get under the keys. As far as I know, if it gets wet, you just let it dry out. But it isn't that easy to mess it up with dirt and the newest ones - with tighter specs - may be even less subject to this. But let's look at it in some detail.
When open on your desk or lap, in most cases there should be little exposure to dirt getting inside. The design is such that most debris would fall to the outside compared to regular keyboards. I supposed if you were using it outside, on a beach, in the wind, that may be more risky, but that would apply to any keyboard. Then there is the matter of carrying it in your pocket where there probably is lint and junk. But when collapsed, the key caps are pressed down, making it very hard for anything to sneak in. I have an older TB (before the improved tolerances) from October 2016. For a long time it just sat on my desk, in stored position, when I got a replacement. Then some months ago I started carrying it around full time in my pants pocket so I'd have it if I ever needed one (I preferred to keep my new/main one at home full time). I don't get it out to use very often, but it does get used so there is the assembly and disassembly a fair number of times. The thing is, it has had no problems with dirt. In fact, recently I took off some keys, just to practice doing it, and looking inside, it was hard to find much of any junk in there. There was some, but I had to really look carefully and nothing that would cause a problem. In any case, you can take the keys off and clean it - something those Apple keyboards don't allow and they have had lots of dirt problems! The space bar I'm not sure about. Oh, I assume you can take it apart, but it may be more risky. I really don't know for sure.
I reported the same in my early experience. It really was awful trying to go back to my regular Apple keyboard. But, even though I have never gone back to practice such switching, I did find, months later, that I could go into an Apple store and use one of their keyboards and feel better about it. Oh, I was very slow, but I no longer felt completely spastic! Others have had to switch all the time because of work and they said they have no problem. But certainly don't be surprised if you experience the same thing as petek at first if you try to go back.