@EzRecoridngs I'm not affiliated with Sylphyo at all, I'm just a Sylphyo owner. To me, it's a very useful tool -- your needs are probably different but I'll give my view of it.
The Sylphyo is primarily a MIDI controller. As a MIDI controller it's very good, because compared to the alternatives it:
-- is small and light
-- has no moving or sensitive parts
-- is sensitive to finger movements allowing you to 'half hole' notes fairly effectively
-- has a very generic set of controls and fingering mappings
-- is frequently updated
This doesn't mean it's perfect. But if I could have only one MIDI controller, I'd have this one.
The onboard sounds, as you say, are a bit 'Star Wars'. But they fulfil a useful purpose -- they mean you can play it with nothing but a speaker/phones connection, so you can work out ideas quickly and practise with it.
From my point of view the faults are:
--no bite controller
--occasional latency issues -- I can't be sure if this is my imagination but I feel like it was quicker when it used an ordinary Midibeam, rather than the new controller. I can't prove it though.
--No custom fingerings, and weird omissions with certain fingerings
--The engineer in me is offended and confused that it needs to have TWO mini synths per Sylphyo.
The internal sounds are useful to have but not a core part of the proposition. It's an expensive MIDI controller, but then it's a very good MIDI controller.