I have heard people state that Code Generators and T4 templates should not be used. The logic behind that is that if you are generating code with a generator then there is a bet
Why does being able to copy/paste really, really fast, make it any more acceptable?
That's the only justification for code generation that I can see.
Even if the generator provides all the flexibility you need, you still have to learn how to use that flexibility - which is yet another layer of learning and testing required.
And even if it runs in zero time, it still bloats the code.
I rolled my own data access class. It knows everything about connections, transactions, stored procedure parms, etc, etc, and I only had to write all the ADO.NET stuff once.
It's now been so long since I had to write (or even look at) anything with a connection object in it, that I'd be hard pressed to remember the syntax offhand.