You still did not answer the question. How many users and how much data?

You never have given any details as the the number of users and amount of data that you were trying to deal with. Access apps done right, can work quite well for companies on a budget. Access apps created by people that don't know what they are doing will always fail. C# with SQL server don't make a good app. Good coding and understanding what the customer really wanted from the start, allows good apps to be written.