I got a rimless tank from glasscages.com that I absolutely love, I think rimless tanks look awesome. Their 20gallon rimless is $209 while their standard 20gallon is $64. Based on that price difference I would assume considerable different construction methods are required for a rimless vs. a rimmed tank.
I've never done it and would be constantly worried about it failing, even adding the additional bracing shown in the video. Even though 20gallon isn't a huge tank it is a lot of water to clean up if one fails.