There is no "perfect" bank which makes all the customers happy.
Most PSU banks have bad customer service and nothing can be done to improve it. the only exception is if you have an account there for many years the staff know you and they are nore helpful.
On the other hand their additional service like ATMs, internet banking and credit cards are ineffective and often non-existent.
It is fashionable in Mouthshut and other forums to bash the MNC and private banks. At least their systems usually work properly. If you are comfortable with the internet many things can be done without going to the branch. If you have "high net worth" you may find some of these banks more useful. You may be right about their indifferent customer service-but do you mean to say the PSU banks have a very good customer service? Some customer service is better than none
To sum up: it is better to have accounts in at least two banks. Make sure that they have a good ATM network(that way ICICI and UTI are better). If you have a long relationship with a PSU bank maintain it, but don’t depend on them for anything complicated. Follow the old proverb about not keeping all your eggs in one basket.
Try to be familiar with internet banking so that you avoid dealing with the bank staff. This way you can avoid problems due to non-receipt of credit card bills.
Make sure that you have at least one bank where all-India cheques can be used. UTI Bank is one of the few who offer this to regular customers. The other private banks do it only to "important" customers-but if you have had a balance of a lakh or so, that is enough to make you important.