In my opinion it’s merely a matter of preference. I enjoy a hammer action keybed, though I did play piano for years before segueing into synths. I don’t consider it a necessity though and a nice semi-weighted keybed is just as useable. My personal favourite is the Fatar TP/9S bed (as found on Prophet 6, Blofeld, Rev2, etc).
I’ve never tried the Keylab, but I did try a A88 and didn’t enjoy the action. I had a Studiologic SL88 Studio, which I adored. But it’s all subjective - if at all possible try out a few and see which you enjoy playing. There isn’t really anything more important.
Hammer is nice but not necessary I think unless you have a background playing piano and are used to it.
The NI S88 had a nice action I thought. I have an NI A ones, no hammer action and I dont use komplete or any NI software but I appreciate the minimalist look.
If you’re not planning on playing classical music pieces for piano do you really need 88 keys? A lot more options if 61 is enough.
Hammer action is quite nice for learning piano playing. In my opinion it doesn’t have much value for sound design and composition.
Various weights, quality, styles of hammer action is how digital piano manufacturers create their specific playing character. If you were shopping for a digital piano, then I would heavily recommend a hammer action. I’d also recommend researching which company/model’s action appeals most to you.
For a midi keyboard, (generally) hammer actions aren’t as highly refined as digital pianos. They are more of a tacked on feature (again, in general). 88 key midi controllers commonly include it because they are flagship products. In my opinion, I’d buy whatever midi keyboard that has the advanced controller features you are after (e.g. chord memory, quick access controls, etc) and just use whatever action it has.
Here’s a way to think about it: can I learn to play funky boogie woogie piano on a synth action keyboard? Any performance would be all electronic with modeled piano sounds anyway.
Arturia can be hit and miss. Either very good or very bad, within the same model. Roland are extremely consistent. You know your Roland, so try an Arturia yourself. IMO they’re very different keys, including the 88 boards.
If you wanna play boggiewoogie, all you need is your butt. Just wiggle.
I don’t think it matters much. Though, I was coached piano from kindergarten though. I reckon if someone has always played a synth kb, then there’s no reason they can’t sound like Stevie Wonder. He boogied on plenty synths.