Ok first of all this bike is really overpriced for its specs and you cant expect it to deliver high end performance in this budget even.Duke has been a good name overall but if you look at KTM RC 250 or 390 then that will make some more sense to but but again its overprices as well.
This bike exhaust is just ridiculous to hear.very bad sound of this exhaust and you will not enjoy it riding if you cant get a thumping sound out of it.for this price you can get a Bullet which can fulfill your desire of exhaust but it lacks on power.
Duke is really heavy for its size and you will be burdened owning this so my suggestion would be to go with other alternatives in this category and have some value for your buck.
No bike is perfect but you can expect better exhaust sound and better performance out of them.
For example apache 200 rtr 4v is only priced at 100000 on road and there is no other brand offering 200cc bike in this category so you can look for that but again that depends on your taste and choice.
Thanks and have a good day.