My initial questions to you (and others) are as follows:
1. How is the bike doing after almost a year?
Any parts not holding up?
My bike is holding up well. The engine is a gem. The cycle parts are good. I however faced a couple of irritations -

- The speedo meter plastic is very delicate and any wipe with a dry cloth will cause micro-scratches that will reflect under light. I touch the console only with a wet cloth.
- The chain needs to be kept clean. Other wise foot pegs vibes creep in - just like the R15.
- The oil filter cap has slight oil weep. Not sure what is the issue - gasket or the mating surface. Not bothered about it at the moment.
- The gap between the 2 rear wheel huggers spray water like anything on the rear shock absorber. Need to do something about it.
- The clutch is heavy - there is no 2 ways about it. My daily commute is 20 kms in peak traffic. The hand does get a bit tired at the end.
- There is a sound coming from under the rear seat. It is heard on hitting sharp bump edges. Irritating. Must be some wire sockets banging on the plastic. Need to fix it.

2. What are the scheduled replacements and cost? (I know the rear brake pad costs Rs.267)

- Front pad costs the same too. I have replaced them at around 7k kms. It will cost Rs.1500-1800 per service. Major cost will be the tyres at around 16k. Based on my bike, they will need to be replaced at around 15k kms mark.

3. Compare it with R15 (not in terms of handling, simply in terms of power)

The power curve is actually quite similar. The bike engine pulls but grudges under 4k rpm, feels best at 5k rpm and above and the power surge at 7k rpm is actually scary under wrong road conditions. Quite similar to R15, just that it has more power everywhere. Other than that, the engine is unburstable during highway runs and never loses composure - again, just like the R15. Speeds of 120-130kmph will seem like 90-100kmph on the R15. Just like the R15 starts straining post 120kmph, this bike slows down post 150kmph. Also, just like the R15, the 6th gear can only be comfortably engaged post 70 kmph.

There is one difference though, the bike heats up in traffic, and if you are stuck in < 10kmph jams for 15 mins or more, the bike will heat up. However, give it a free run, it cools down just as quickly.

Other than that, I am not sure if you have noticed, on the R15, there is a cyclic RPM surge and drop at around 3k rpm when the throttle is held constant in lower gears. The same issue is there on this bike too - just that the increased amount of power makes this more apparent and hence is a bit irritating in slow moving traffic.

The brakes with ABS is good. I have had the (mis?)fortune to put them to test a couple of times at speeds between 20-80kmph. Never a skid and always stopped before the expected distance. However, at low speed and riding over gravelly road, the ABS will prolong the braking distance a wee bit as the tyres can not lock and dig in to the road. The lever push back takes some time to get used to.

The lack of fairing is both a blessing and a curse. Blessing in that crosswinds are not felt at all unlike the R15. Curse in that, anything above 100kmph, you are basically hanging on to the handle bar for life - the wind + the acceleration will make sure of that! I needed to get a windshield fitted on. And that took care of the problem.

The suspensions are stiff and are similar to those of the R15.

The handling is at par with the R15, just that it is more flickable than the R15. Also, coming from the R15, it takes some time to get used to.

4. How is the SVC response and quality of workmanship? Cost of maintenance (other than tyres)

Better than the Yamaha SVCs. However, I do not have much experience with them apart from the regular services. Cost is as mentioned above.

5. What does your heart say, a year after owning this bike?

I would say, with the R15 setting the bar so high, this bike still feels like a definite upgrade in all ways. The outright build quality will seem a little lower (the plastics mostly), however, they will hold on just fine. The power is amazing and with the rest of the package is actually usable. In the initial days, used to get a feeling of superiority and almost used to feel disdain for other vehicles on the road - power does corrupt. Other than that, since I use the bike majorly within city, I have 2 complaints - the clutch lever should have been softer and the rpm surge issue should have been not there.

Before buying this bike, I felt this bike would have been the best bike to buy in 300-400cc range in India, and now, after almost a year, the conviction remains.

Sprocket issue have been rectified and replaced by the company for free on all affected Duke (again a design defect) Secondly, very early batches did have some oil leak issues, busted seal, all were taken care of promptly. Secondly the oil leak was a design fault in and of itself, not a manufacturing defect per se. Newer models have been rectified with such issue and yes occasional issue does pop up.
Reliability for now, most owners are happy even all these niggles have been sorted by the SVC promptly. If you'd recall, the CBR250 had it's fair share of issues when launched in India, but all were promptly rectified in the further lots continually. And I don't think KTM is too is on the right track. Think of this when you manufacture a bike ground up, certain issues do pop over the long run, but all issues are continually being rectified and improved by KTM engineers.

All SVCs in my opinion are not the best. You see, an chap at the SVC either can make your day positive or negative depending upon the bikes they handle on that unfortunate day your bike is in the SVC. Less bikes = Good job, more bikes = Delay, clumsy work, high chances of repeat visit. It's been the case in all the different brand of bikes I've owned.
Compare with R15, simply in terms of power = (Need I elaborate more?) Not to diss the R15, it's one of the best 150cc bikes one can lay their hands on. The problem with enthusiasts is this. Whenever they see a bike powerful or that has a little more oomph than theirs, they immediately start comparing it to their bikes. It's not a bad attitude per se, but just a little wise thought would yield the desired results. Remember, each motorcycle has its own character, pretty much like a human being. You can't compare Sachin Tendulkar's skills with that of a Marc Marquez, though both are excellent sportsmen in their own way. Just so you get the point.

Cost of ownership is not too pinchy on the pocket, nor is it affordable for a common man. The oil price alone would make a lot of folks to reconsider. But if you can own it, you definitely can do the bills. If you can't then don't buy the bike. I always say.