GSPANNU, 520d to 535d , thats going to be quite a jump!
You may recall you help code my car last year, I finally got round to coding myself and managed to set the auto stop start to last memory last week.Very nervous doing it but it worked first time.I might just add HUD indicators as my next step, thats the only other thing I really want thats not already on the car.(Hoping that when teh car is services, the integration levels are not changed forcing an upgrade of e-sys / psdzdata / token)
Regarding suspension, I have a 530d on 19" wheels with the passive msport suspension and this is if I';m honest, not a good as I think it could be.
Perfect on motorways and fast roads but around town where there are potholes, it can crash and can at times feel unsettled.
The wide tyres do tramline as well and you can feel the car pull when going over road markings.
I'm not so keen driving it around our bad town roads but feel the car with this suspension is more suited ot the faster roads.Its not as good as the E39 I previosuly had with 18" wheels and msport suspension. That felt more planted even if a little firmer. I've not experienced VDC myself but reading through these forums, most people seem to feel this is a better setup.
R adaptive LEDS, if you can afford to do so, go for them, not sure if you've seen this,
Thats convinced me that they are very good.
Ithink the thing to bear in mind is that the 5 is a large car and I think its more luxury than sporting. It doesn't feel as sporty as my old E39 but then it is considerably heavier at nigh on 1.8 tons.
as GSPANNu has said, I don't think VDC has anything to do with the gear ratios. I would suggest the sport auto box with the paddles.