I've done St Louis -> Colorado Springs in a day in the ID.4 and the seats are quite comfortable for longer trips. The massage function on the upper trims is nice to prevent stiffness on those long trips.Agreed WRT glitches. GM had several years of experience from EV1 and Volt, yet still had some glitches.
Interior was very nice, I test drove Pro S gradient, the look and feel is quite upscale vs Bolt (I have not seen 2022 Bolts yet, so can't make a comparison to that). I wouldn't call it luxury class, but certainly not Econo class. Seats seemed comfortable, but I was only in the car for 15-20 minutes so hard to tell what longer trips might be like. The ride was more refined, though I think we had the settings for Comfort level, the Eco and Sport modes might be a little less "luxury" ride quality? Massaging seats would seem to provide even further relief, though I didn't try that feature out.
Regen is not as aggressive as Bolt, you will have to use the brake pedal again! Rumors are that might change with SW updates. Sport mode is supposedly a bit more aggressive with regen. The only time regen will bring you to a full stop is ACC, but again I can't attest to that with my limited exposure.
I found the Brake\Go pedal a bit close for my large feet, had to be a bit purposeful in switching between pedals.
Regen is definitely less aggressive and I missed the paddle at first, but I've gotten used to backing off a bit sooner in B mode and generally only use the brake pedal when I need to come to a complete stop. I do wish they would implement OPD for smoother stops, GM completely nailed it on the bolt! I hold out some very small hope that it might come in the future as an option via OTA update...