It's kind of off-topic already since this is not a piano related discussion but as you know I also use some software synths and needed a very compact 49-key MIDI controller with a very fine (channel/mono) aftertouch. I already have an ASM Hydrasynth which is a terrific hardware synth keyboard with awesome polyphonic aftertouch, however I use it also for gigs and it's a bit too wide to fit my tiny desk. I found the Nektar GXP49 to have the required features but there were no reviews, especially if the aftertouch is linear, smooth and usable. Well, I found it for €165 at Muziker (a European online music store) and decided to order it. Just arrived and I tested it.
The keys are too noisy and clacky when released but that's the only complaint I have. Other than that it feels very solid, the aftertouch is indeed well-controlled and I can create a smooth and linear gradation without breaking my fingers, so I'm happy! The action is very light, it's a synth-action after all, so not your piano controller. Not sure who would purchase a 49-key keyboard for piano anyway 😀 It's USB-powered, so no need for an adapter, the pitch bend and modulation wheel are very nice feeling, solid and with good rubbery touch, compared to the usual wobbly wheel on other keyboards. What is very nice is there are multiple buttons for DAW-integration and their software for the integration with Logic even supports Apple Silicon M1 natively 🙂
So, initial impressions are positive and I would recommend it based on that.
P.S. The velocity response is good too, I tested it with acoustic and electric piano patches in Logic and it's more than sufficient for non-critical piano work, e.g. in modern arrangements. Of course, for solo piano work you need a hammer-action controller with 88 keys, preferably with real acoustic piano action 🤣 But you already know that.