Hi - I had this same dilemma a while ago when I ordered mine. My new G3 arrived last week (and I'm loving it) and I'm glad I didn't opt for the G4.
I weighed up the key points:
- Leather - nice but not essential and the cloth, faux leather in the G3 is good.
- Sunroof - had them before and rarely used them.
- Pre-heat/app - nice idea and this was what nearly tipped me over. However, the savings over using the engine to heat the car are minimal, certainly nowhere near the cost of the extras.
- Reversing camera - I had a great one on my last car as well as sensors. Not sure why Mitsubishi went down the one or other route, but the camera is a bit naff compared to my last one. Guide lines only come on after about 30 seconds from a cold start, plus they are fixed and don't show the car tracking.
- Chrome trim - not fussed
- MMCS - would have liked to have it, but have a separate and better satnav and all the driving info would just be a distraction over time, I suspect.
- Elecy boot - nice idea, but slow and beeps a lot.
The above may seem 'sniffy' and of course it's all personal preference and experience. For me, none of the extras were worth the extra lease costs, but naturally for someone else they may be. If the difference was only a few hundred a year (which it clearly wouldn't be, I know) then I would like to have them (although the camera is a bit naff).
Good luck in choosing and really you won't go too far wrong with either. I'm lovin' mine!