My first microphone was a borrowed-long-term Sennheiser from the e800 series but I'm unsure of the model. It was as dynamic as you could want and had incredible output and the amount of gain before feedback left nothing to be desired. When my friend needed his mic back, I needed a new mic.
I had heard that the Shure SM-58 was the industry standard and thought, surely as good as the Sennheiser was, this Sm-58 must mop the floor with it.
During my first gig with the Sm-58, I learned better.
It had a tinny and dimensionless sound compared to the Sennheiser and the amount of output was so much lower than the Sennheiser that I broke my desk trying to push the faders to get that volume and fullness i was used to.
This sent me on a wild search to find the right mic for me. I bought the Sennheiser E845s thinking it was the one my friend used to own but I know now that it wasn't.
Be that as it may, the E845 is a great little mic and although it's output level is only just slightly more than the SM-58, it still manages to give me the dimension and dynamic range I need to feel my own voice during a performance.
It also handles feedback incredibly well.
If I had to do it all over again, I'd probably save up a bit more and buy something from Senheisers' e900 range or a Shure SM-58 BETA. But I'd still carry around one of these as a worthy backup mic.