I disagree with having to do any change to the 2015+.
Lighting is good, especially with a silverstar ultra2 h7 bulb.
I don't suffer from anything throttle related so I cannot advocate ecu flashing.
(I have read the articles and I'm not impressed by any curves).
I'm happy with the throttle and the low rpm response as it is.
As for LT or not, I'd say no LT. You won't care for these awful rounded plastic (side-opening - to make it worse) boxes.
And the handguars are crap. They rotate up on a crash, taking out your clutch cable or master cylinder! And it's junk metal too, soft and stripping hex bolts you cannot tighten hard enough. You are better off buying your own handguards (if you care).
I guess if you never rode a MK-1 or MK-2 you wouldn't notice any difference. That was the first thing I noticed when selling my 2007, yes I was disappointed but lived with it. I can tell you with all honesty, installing a booster plug might do it for you, but if you read the thread on this you will realize it is nothing close to having the ECU flashed with a good fuel map.
If I put my bike beside a identical 2015, you took both out for a ride, once you returned you would say there was something definitely wrong with the other bike, and I am talking a huge difference.
I will go one step further, if I had my original 07 , which had the TPS tweaked and the vacuum hose mod, have you ride it then my 2015 with the new flash, you would find the 2015 performs equal to but better than the 07. Not trying to convince anyone, but riding and experiencing is a lot more accurate than looking at a chart or curve.
Yes I posted this on the UK Versys site, several members said they don't ride in the below 4000 RPM range. I would say 30% of some of my rides are in the 3000 to 3500 RPM range now, nothing like being able to accelerate in 6th gear at 60 KM/HR, try that with a stock ECU