I have only had my I-Shift for 3 days (currently in garage for major problems), but prior to this I did feel the gearbox was jerky when changing. I was hoping it had something to do with the faults it currently has, but unfortunately not!
It is most noticeable when slowing down say at a junction, then putting your foot down to move - it seems to shudder / jerk forward!!
My last car was a Mazda 3 with a tiptronic gearbox, which was always a smooth change - so maybe I just have to get used to a different gearbox! or get used to changing manually - but then don't want too - otherwise I would've bought a manual in the first place.