Glass Bottle Cutters... cool'n'fun or just a waste of bandaids?

[aimeesrockworks]

This is just for me and my serious need to be extra crafty this time of year... no business ever intended.

I wanted to make some of those fancy-pants recycled glass cups for some friends.  I've seen a bottle cutter at Michaels and thought it might be a good use of a 50% off coupon.   

Am I wasting my time?  Is there more to this craft than cutting the tops off and sanding the edges? (well, I'm sure there are more professional methods but this is just for fun.)

[MakinTheBestOfIt]

I've seen those but never tried them.  Will be watching to see if anyone has used them and what they think.