No problem with being tripped or getting snagged. They did provide decent traction before the rubber on the bottoms split (both broke where the rubber crosses in the front).
I'll hang onto them for slipping over Tevas or sneakers next summer and for light use only. If the Pro model holds up better, I'll post.
I wouldn't recommend these for a night on the rocks and if you have a choice, save the $20 towards Korkers. (I got these at 50% off this summer when all my local shops were out of Korkers in my size)
Krispy, Korkers sells what you are looking for too.
http://www.korkers.com/sport/felt.htm
Looks like something you could probably do yourself if you've got spikes and felt.