Thanks to OP for this thread as I am now going through exactly the same dilemma choosing between R and GTI. I think the choice depends entirely on what you're looking for from a car.
I do about 5k miles a year. Commute to work is only 4 miles each way in town traffic. I drive country lanes, dual carriageways 3-4 times a week and motorways maybe twice a year.
I'm at a point in my life where I want a nice, quiet, refined, easy to drive car that's still not slow and can deliver a bit of fun and speed when I'm not snarled up in traffic.
The R beats the GTI hands down off the line but in "real world" driving, I keep hearing there's not much of a performance difference. Extra 60 BHP in the R but then 100KG to lug around with the AWD.
I'm swaying towards the GTI because it looks better than the R in my opinion, exterior and especially the interior. It's also is a more practical car and better suited to the miles and type of driving I do.
Also, whilst there's not much difference in price which does make the R tempting, I could get some great options on the GTI for the extra money.
I too though would be interested in others views on what to go for.