I used to love the Martelli cutter til my arthritis got too bad to use it comfortably. If you have a problem with the spring Martelli will send you a free replacement spring.
I did use the Fiskars, but that is sometimes awkward for me. Now I use the Olfa that has a squeezy handle.
I think it depends on what feels right for you. Try them out. I'm sure your quilting friends have a variety of rotary cutters between them that you can sample cut with. For example there is a Gingher [I think] but it way too heavy for me to use.