Will the extra 10BHP make a difference in performance? Not really. Will the extra gear make a difference?Probably a bit.
It's all about perception. The latest and greatest will always be desirable. Do I need a new iphone 7 when I have a perfectly functioning iphone 6? Of course I do. We always want the latest, becasue we perceive it to be better. And remember the Golf update will only be slightly and sufficiently different so it can't really polarise opinions.
Think the slant is that those received an R say in last year or very recently will feel like they missed out on anything tangible and maybe should have waited?
If ready for change now, of course it will be nice to point to a minor uplift and a shiny piece of tech and gizmo, but think the present Golf is at such a high standard from the move to MQB and some of the other lifts from the MK 6 that the improvement wiggle room has really closed to minimal.
Be much like the I phone now, lots of glitz and ceremony at release with lots of smoke and mirrors but when you settle into the reality there was little substance to any of it.
Think present owners can rest quite easy on the uplift and even the MK 8 as personally feel they might go in a direction that personally do not want to go of more screens, UI and touchless interiors, and integrated tailpipes! really yuk!
By way moved from an I phone 5 to a 7 this year and though bigger and faster, the headphone change is definitely as step back, so be careful of what wish for as sometimes these companies are so desperate to wow, they make changes that are backward steps (so much for wireless, as have another adapter from Belkin now to offset the charging/listening issue (decent blue tooth headphones on Christmas list)