well since no one else has responded, i'll take a quick stab at it:

most USB mics in that price range will be very similar. i'd suggest that they will be close enough so that any difference does not really matter.

that said, the Snowball is a pretty fly mic, even for regular (non-usb) microphones.

i have a few mxl microphones (none are the usb variety) and i've been disappointed with them. they're usually the last to come out.

I have a few mxl microphones (none are the usb variety) and i've been disappointed with them.

I've never been impressed with Marshalls myself.
I imagine the Blue would be worth the investment.

USB mics seem like an odd idea to me in a critical recording environment
(webcams and multiplayer games come to mind when I think about them).

Well thank you guys for answering i apreciate it ,but ia have sorta of a delema maybee one of you can help me with . I have shure mic shure 58 and y wanna record myself at home. now the problem ios i don;t have a very good sound card just avarage so the line to go in my pc is like a mini plug i have treied to buy a cable xlr to plus the shure mic in my poc to reord with that , but the volume is very low etc of the mic. So i thought maybee a usb mic would be better cause it's via usb and maybee better to record my voice like the snowball from blue , so what would you recomend buy the blue mic or stay with the other one but look for a way for it to fit, sorry if my enlgish is noit the best i am from curacao and island in the carribean thank isn advance

It doesn't work like that.
Mics don't go into soundcards.
Nor should mics connect into a computer via a USB cable...

Get a 1 or 2 channel preamp w/ XLR inputs - A firewire A/D preamp box, you'll be right as rain.