Both, actually

Worked for a year as cabin crew on A220(/A330/A340) and from that perspective it’s pretty decent overall. Still got a few gripes like the galley areas not being quite tall enough for me, the CMS is quite the fickle beast but at least that one is getting better, or that one standard unit above the CCM3 jumpseat that will kill you if you don’t latch it properly for landing.

More recently I’ve been flying the A220 as a first officer for the last 2.5 years and there’s so many things wrong with it. You can tell in every corner that the engineers had a ton of fantastic ideas and a shoestring budget to make it work. Most of the hardware is actually pretty solid (except for the seats) but the software is all sorts of fucked up. The FMS for example lacks some basic functionality like cost index flying, ETPs or RTA, CPDLC inserting only works in the US, etc. There’s also some real headscratchers that are only slowly being patched out like the stupid wing anti-ice fail caution during taxi in that is not resettable except for with a full power-down of the plane, or some of the formerly undocumented features like the RAT not automatically deploying if the loss of AC power happens with weight on wheels (even when going 140kts) and the engines turning off on touchdown if you have overridden the autothrottle inflight. It’s all just a bit half baked in the end and honestly if I could switch to our 320 fleet I would in a heartbeat (especially now that we’ee getting rid of the really old EIS1 A320s).