Although I've had the JLC Saw for a couple years now, enough can't be said on how useful this saw is. I still have the old Airwaves saws, and really don't use them anymore.
I've also had the UMM-USA scriber for over a year, and it too is a must. The best thing about this scriber is the fact most surfaces you can use for scribing, scraping, or whatever.
Another scriber I really like is the
RB Productions one. Different than the UMM-USA one, but I like it too because you use a standard X-Acto/Excel handle which makes it easier to handle than the UMM-USA one. In addition, it's better than the other non-UMM-USA scribers because it doesn't leave a ledge, easier to handle, and it's serated on one edge that one can use on round-ish surfaces.
I've also tried a couple of the RB Productions saws. The best one is curved, with the serations on the down-facing edge (if that makes sense - look at the link above for pictures of it). This really helps with removing resin parts from pour blocks, as well as removing control surfaces from aircraft. Nice! Again, advantages with these saws is you can use them in standard X-Acto/Excel handles.