I've been using Aptosid (formerly Sidux) for about 4 years now and never had any problems myself. I had heard that Debian Sid was unstable and for experts and sadists only. (Side note, Aptosid is only half unstable, other half are stable packages) One day I got curious and tried it on a virtual machine. Liked it so much I soon did a dual boot with it and another version of Linux and it has become my distro of choice. Don't take anyone's word for it, even mine! We all have different tastes with what we like and what we are comfortable with. Some people like stable and some would rather be on the cutting edge. If you're scared to take the plunge try Debian Testing out on a virtual machine and get a feel for it. Good luck!