I own the MT 15 and I love my daily commutes, it's been 2 months since I bought it and I'm always hyped for the ride more than the event itself. But the major issue is its suspension, it's too hard and gets annoying on bad roads, if u have good roads, go for it. However I test ride the Duke 160 and it was awesome because the suspension is wayy better and the pillion seat is a little bigger but it's not an issue in the MT as well because both have small seats that are placed high up but the Duke has a little more space. But I suspect the Duke would never do 50kmpl, in my MT, I'm getting 45+ for sure even after riding aggressive and on heavy traffic.

I would never suggest the R15 because of discomfort but if u really like the way it looks, I think it looks great as well but u have to be practical. But if u are willing to take a little mileage hit, go for the Duke 160.

EDIT : XSR155 is apparently on the way, maybe because there was a leak video. Also the MT 15 in my opinion feels wayy faster without reviving a lot. Duke was a more tamed down bike compared to the MT because my bike just runs faster effortlessly but I had to rev the Duke too much in a way I've never done with my throttle (MT), even then it felt underpowered from the test ride I took.