Haven't used my Jolla C that much as I'm still in the process of copying & migrating stuff, but my experience so far is positive.

The device feels much more responsive and it seems like you can yet again properly multitask without oomkiller ruining the show all the time.

Also the screen IMHO work much better than the Jolla 1 one - much better visibility in averse light conditions.

The main donwsides are IMHO probably the missing TOH interface and missing magnetic compass & gyro sensors - which effectively preclude using most AR apps. But oh well.