Gybing the spi when I'm sailing singlehanded has a lot of other problems than just messing around with twice as many forestays as the sloop guys, so for me it's not an issue.

Strandberg/Mattson used an early version of the snail which could casue wear on the spi, the later versions has removed that problem. Note that my M20 snail is of the early type too, but one of the reasons why I haven't seen any wear that could be traced back to the snail is that I only have a 16 m2 spi inside it. All snuffers systems wears down the spi more or less but I'm not sure the snail is worse that a tighly packed snuffer.

/hakan