I had all three and ran my own tests and couldn't hear much of any difference between the Shure mics. While I think the SM7b is worth the extra $$ in design, with some mic skill and the same distance the 58/57 seem to be 90=% the same sound as the $400 model.
$100 is impressive at $400 the expectations are really high, imo.
I regret selling my SM7b in some ways, but now its hard to buy it again at $400 when I know the sound of the 58/57 is so close as the videos confirm my own tests. I always have a bunch of 57/8's around here etc. (Im surprised WARM and BEHRINGER aren't making copy-clones of the SM7b for $200? )
The Bulky design of the SM7b can be a plus or negative, the SM58/57 can slide into areas easily, and take a standard mic stand etc..
ARCAXIS....You mentioned that EV CO9 mic has that extra gain built in and no need for a Cloudlifter$$$ booster. SM58 -54 db,
C09 at -49db, Sm7b -60db...(SM7b Cloudlifter adds 25db but costs $150 plus another cable $10). The C09 is probably a good mic for this low gain preamp. (see recording hacks overlay pic below...C09-purple vs 58 and 7b-orange)
great videos on this thread. I really liked the off axis examples and keyboard clicking on the first one, again I couldn't hear a difference much between the three either. Maybe the largest difference is the visual? I was getting ready to re-buy a SM7b, but will wait now.
good luck Twiky, 2i2 + SM58....slap on some plugins get back to recording..