To Beta or not to Beta
The SM57 is an iconic instrument mic, and the SM58 is supposedly the "Industry standard" for vocal mics. They use many of the same parts, but have a different windscreen, which DOES make them sound different...The SM57 is more boxy and close sounding to my ears, and when used on vocals has kind of a mid-frequency honk, which can be good or bad.
The Beta 57 and 58, are even more alike, with (once again) different wind screens, that make them sound very slightly different.
After using all of the above in both a live and studio setting, I have declared a winner (in my own ear/mind)! The most versatile of the bunch is the:
Beta 57!
It is by far my favorite live vocal mike for quieter singers (especially quiet male crooners), lending a closeness and superb intelligibility, yet maintaining a fairly true frequency curve. It sounds about the same as the Beta58, but with the ability to get closer, edging it out in my book. And the output is hot enough that you don't have to crank the gain.
On instruments (snare, electric guitar, suitcase Rhodes), it has as good of SPL handling as its non-beta counterpart, and MUCH more sparkle! This means it's more versatile, but also means you'll have to EQ if you want the classic 57 sound.
It's also MUCH more durable than the SM57, strictly due to its removable/replaceable mesh screen. Have you ever seen what happens to an SM57 snare mike that has had one errant stick hit land squarely on its plastic end? Not pretty!
The only live situation I haven't liked
my Beta 57 for is loud, high, female vocals, where it can make them sound more harsh than the average (crap) Mackie EQ can remedy.
My .2