My GTD will be at end of its lease not too soon after yours and will be sad farewell really as truly love it.
But nice out of the box new is kinda fun in the choosing so embracing that at moment and have pretty much narrowed myself down to three options:
Golf R
Golf GTI (PP)
New Tiguan R Line
So interesting that you have decided to go for the R from the GTD.
Firstly I would choose Pure White on all those listed above as its a great colour for enhancing features and keeps really well throughout a year, you only know how dirty it really is when wash it.
Love blinging shining black, but would avoid black totally from previous experience of Plain and Metallic as you truly have to maintain it so much to avoid the dusty/dullness, swirls and highlighted bird mess.
Love Lapiz Blue but given have to park on road the white is more understated to the uninitiated, so as much as like the attention, it screams R too much perversely.
As for the 90% tints, definitely in the consensus here as the standard tints are perfect, easily noticed as contrast on my GTD but with some subtlety to.
On the Black Paint think you are in danger of taking the sophistication of the R into Corsa racer boy territory opposed to stealth look maybe seeking - as with all these things my subjective personal opinion.

Think the most interest that have in you moving from GTD to R is how feel on fuel consumption, as its a big leap from a GTD.
Obviously know the MK 7 Golf well now and so know that either a GTI or an R will make me very happy, it really will be down to how much fuel consumption willing to give into for that little extra

The new Tiguan looks great though in R Line form and has lots of MK 7 tech and interior feel as well as that LCD/HUD display. It also has 4 Motion and GTD power unit, so its a tempting, hugely sensible package
5 door manual - 5 door is a must if carry passengers as biggest pain ever in 3 door - DSG convert, cannot imagine not having it, DSG and Auto Hold are the perfect partners
Deep Black - Not for me for reason stated
Keyless - Not got at present, would likely spec now though
Rear view camera - Sensors are more than fine for me,
DCC - Total convert, maybe a must on R with Pretorias
19" Pretoria wheels - The best looking wheel on the R
Tinted 90% glass - Would totally avoid.
Must adds for my next are the Apple Car Play and if not standard winter pack for the heated seats