I was a super hyped for Polyend Tracker right until the Loopop video. No polyphony on tracks, samples in mono only, only 1 note column per track, only 2fx columns per track, 90sec sample limit, single stereo out channel, granular synth limited to single grain and probably more limitations that I'm not aware of. For me personally, at €500 it seems a bit irrational to choose it over Renoise which cost me under €70 and can run on a shit laptop. And since it doesn't open xrni files (but reads .mod files, that's cool!), there's not much point having both around.
The only real advantage it has over renoise on a laptop is probably being performance friendly. However, in that case I start thinking of hooking up something like an apc40 to renoise and going crazy with mapping out macros and phrases etc etc etc. Provided that the premise of "everyone has a laptop" is accepted, renoise + apc40 still comes out cheaper and offers much more customization and flexibility. That being said, I understand that it's the limitations of hardware that often force you to become creative, I don't feel like this piece falls into the category of that type of hardware.
Overall, it really does look well-engineered for the price they're offering it for but I'm not 100% sure on what niche it's supposed to fill.