I don't have any problems with detaching too easily while road biking with frogs - I'd say they probably detach too easily for really technical mountain biking... but then my mountain biking abiilties suck, so that's not really a biggie.

I do remember the bf sticking some shims under 1 pair of my cleats - nowhere near as involved as that frog surgery thing, I think he just cut something and shoved it under the white plastic piece - no gluing or trimming. I don't remember why, 'cause it was on my first pair of cleats that we mounted (they were used cleats)