The telematics loom won't be in place. This will be the hardest part technically.
The NCDC 2013 and 2015 are identical units, except the legends on some buttons are better.
The telematics is 900Mhz GSM only. Which in the UK means O2 or Voda, or their MVNOs (Giffgaff, Tesco, Asda etc).
The upside of these hassles/limtations is how well it integrates, and how well the phone works compared to portable handsets, esp in weaker signal areas (my gayPhone on Vodashite doesn't work in my road, yet telematics on Voda gives 3 (out of 4) bars of signal, and holds a call well).
The upside of a simple BT system is cost (at CW-7K can be grabbed for £20 second hand), ease of fit, and just having one number to be contacted on (and only having one SIM to maintain).
Personally, my MV6 (the car used the most) has both telematics (on a different network to my iphone, O2 in my case, as has the best 2G coverage) and a BT kit for my gayPhone. The Elite has just the BT kit.