Those look similar to Aerotech guidesI like rail guides myself. I think they look more like an actual rocket part (I'm kinda weird that way ). I guess they can be a bit finicky to get started on the rail sometimes, but it has never been an issue worth mentioning for me.
I use the Acme aluminum guides and like Speaknoevil said, I cut them in half. I always use JB Weld to stick 'em on the tube. I dremel some fairly major cross-hatch on the back of the guide and strip the tube down to fuzz, or heavily scuff fiberglass. If it is a bigger, heavier or faster rocket I like to drill a couple of holes through the middle of the guide and into the tube so that the JB mashes down in there good and makes a little rivet, just for extra mechanical bond. Never have had one come off yet.
You can see the two little holes (sorta) in this pic.
View attachment 418624