Hi,
I am looking for a new full size keyboard with ISO layout (preferably German QUERTZ but any ISO is fine) and linear switches for up to 200-300€ as a gift for my brother.
Would you consider a MX-Board 6.0 a viable choice? How does it compare to e.g. a Filco Majestouch in overall build quality? The keycaps are a (obvious) weekness but they are subject to change anyways...
(If you wonder why I ask such awkward questions: I don't have any higher quality keyboards but a MX-Board 6.0. Would like what I could expect from companies like GMK, Ducky or Filco.)
I've owned an MX board 6.0 previously, and I actually just got an MJ2 in the mail the other day (what I'm typing on right now) so I feel like I'm uniquely qualified to answer your question, haha!
Anyway, the MJ2 definitely comes with better caps from the factory, but as you said, they're subject to change, so that's a somewhat irrelevant point. I really like the plastic used on the MJ2 body though. It's a really nice texture that's an absolute pleasure to handle. I also think it looks a lot better than the MX board, but I really like board with no LEDs, and more subtle looks. The casing on the MJ2 is as durable feeling as the MX board, since it has a steel plate. The MX board has a steel plate, and an aluminum fascia, so if you're into the aluminum top thing, that might be the one to stick with. The Filco cable is also really nice for a non-braided cable, as it's super supple, which is really nice to see. The switches are the switches, so I'll leave that to you, although the MJ2 is definitely available with a wider switch variety.
I personally like the MJ2 better, but it's mostly an aesthetic thing. If you like the MX board, there's no reason to change what you have (although I believe that even now, the MJ2 is a far less expensive board from new - I paid $250 for the MX board when it first came out, and I just paid $140 for the MJ2.)
The MX board is a really good keyboard though, make no mistake!