Microphones

[sam.spoons]

That doesn't make sense to me Lee, The 57 and 58 share the same capsule, the polar patterns are identical and the frequency response similar (the 57 has a higher peak at 5-6kHz and more bass roll off but also more proximity effect 'cos of the smaller grille design). On paper they should by virtually identical barring the small frequency response differences. If you're comparing the Beta's they are hyper-cardioids with a much tighter pickup pattern.

Not suggesting you're wrong, I'll try them side by side when I get the chance 

[RoadRanger]

The difference is that (like the OM7) you can get your lips MUCH closer to the diaphragm and gain about 6dB over the SM58 .

[sam.spoons]

Yes, that makes sense 

[WK154]

Lee your on to the key to all this. When a Singer finally graduates and becomes an Entertainer all the tools ( body, facial expression etc.) including the mic are used. Watch American Idol and pay attention to Jimmy the Mentors and Judges you will learn a lot. Yes drool over the equipment they have at their disposal I do. Whether you use the proximity effect on mics or not.