Photek pointed out all the worthwhile information for you.
As a Das Ultimate owner, I didn't mind the ABS caps, though I've since replaced the majority of my keys, with zinc alphas and blank white PBT caps. I've also gotten rid of the glossy surface by putting carbon fiber vinyl on it (
pic).
The aesthetic is clean and simple, and if you're diligent enough at keeping the glossy surface wiped down, you won't have many problems. That being said, if you have animals, have your computer in a dusty area or the like, it could become an issue. A can of compressed air might not totally work, as some dust and stuff can kind of "stick" to the glossy surface, requiring a wipe-down.
As for similarity to a TK, I can't specifically say. I've only dabbled on a TK in a store, but it was pretty similar from what I can recall given plate-mount, etc... Although, I'd almost say the Das feels a little more "substantial," but maybe someone with more experience can comment.
I don't regret my Das purchase as my first mechanical. As a second keyboard for you, with blue switches already...meh. Unless you put a huge stock in the aesthetics of the Das, throwing blanks on your TK is going to be a pretty similar experience overall.