I own a Vista, bought a year back, apart from plastics, i did not find anything of inferior quality. If you open a bonnet, you will realise that everything seems to be good quality and properly placed. Seeing the engine part, you can easily say that it is not like a typical tata car as it used to be.
My friend recently got an opportunity to travel by Manza, even though in his life he has always suggested a maruti and hyundai car, his perception was totally changed by the comfort level it had. He was also surprised to see the same comfort level offered in Vista.
So friend, all and all, tata cars are not that bad as it has been portrayed. People who are saying this have never used such car. Also it is a general tendency to show people that whatever they have brought is ultimate, especially after paying 50k to 1 lac more. They will always try to bring down other products.
Manza will do the same job for 1-2 lacs cheaper what Linea or other car will do.
Now for service part, i did not find any problem with service.
No car is perfect, but when it comes to Tata, they are many times more exaggerated.
I remember reading a review of Ritz on mouthshut, where a stone hit the engine, which leaked entire engine oil, causing the engine to cease . Rather than complaining of design or quality fault, he was suggesting other owners to drive carefully on pebbled road and regularly check the bottom of engine. If same would have been the case with Tata cars, he would have suggested not to go ever in life for tata cars.
Other thing, what i always do is that i learn about all your deficiences or issues of the product and then decide, this will restrict your expectation, which is endless and you will be happy with your product. I know it sounds funny but then it has always helped me.
I have always adopted this approach, whether it is bike, mobile or car, so my brain is always ready expected problem, rather than shock and trust me i am happy with all my products.