LOL! That is probably the best comparison I've seen and it fits my feeling after using the TB and then going back to something else!
Other than the special case where someone needs something that works on a non-flat or a soft surface, the only thing I've ever run into that is consistently more difficult on a TB is when doing something "casually". That is, something where I'm not actually having the TB set up in typing position, but rather something where I'm going to reach out and have reason to hit a short series of keys for some reason.
The problem is when something is on the green layer (numbers and most symbols). I have a habit from traditional keyboards where I'll try to use one hand to do this rather than get myself in a normal typing position and I'll use one hand. But doing this with the TextBlade would require some significant stretching with one hand and the finger angle changes a lot based on what you are reaching for. So, since it doesn't have totally separate keys, it can be easier to reach for a key, but have your finger register a character on the same key, but not what you want. Especially since I tend to be impatient rather than taking my time in that odd situation.
For those who may object to not being able to use the TextBlade on your lap unless you also can lay it on a solid platform, they might want to think about how other keyboards do it:
They are much bigger - which will give you a broader support on your lap.
They are thicker - which gives more rigidity.
They are much heavier, because of item 1 and 2 and other things.
So, while this is certainly a "weakness" of the TB, it is a simple matter to duplicate the ability of those other keyboards - simply carry an item that is solid and you can place the TB on it (I used a plexiglass sign and set it up with a thin piece of steel in the sign area so the TB would "stick" where I put it). That is fairly large, of course. But mostly only in depth. The length is essentially the same as the standard Apple wireless keyboard. The thickness is much less. So if someone is more creative, they could make a board that fits the exact dimensions of the Apple keyboard (like a piece of thin plywood - though you might need to be handy with tools to get a piece of thin steel embedded if you need that stability).
The result would be something thinner, but otherwise the same size as the Apple keyboard or even less depending on taste. And also much lighter. Sure, some may say that "board" makes things less portable. True. But it would be as portable as most other options. I could even see a way you could create a folding board to make it more portable (though I don't have the engineering knowledge to know how to unfold it and have it be rigid enough to make for solid typing).