I have Veloplugs. I like that I don't need to worry about them shifting out of place like my rim tape did. Also, supposed to make changing tires easier since there's more room inside the rim without the tape. Can't say that I notice the weight savings, but less spinning mass out at the rims is supposed to be a good thing.

The plugs didn't fit the stock wheels that came with my bike (the spoke holes were too big) but they fit great in the Cane Creeks I switched to.