I am using Harrier form last 2 months and I am extremely happy with car performance specially the build quality and superb stability of car.
As per my driving capabilities I can get 14 in city and 19+ on highways without any issue.
Sunroof and performance of automatic gear unit is top notch, I will suggest people to take test drive multiple times to get feel of it or any other car.
Some places fit and finish is something Tata folks should work. On it. But majority of time it's tough to figure out but if you are very conscious about it than you can figure it out.
For me steering is pretty good as it gives better control and response but few people feel that it's bit not so smooth like suv700.
I will surely suggest you to go for test drive. Later you can decide on it yourself.