Actually, Halcyon doesn't see any problem with the integrated STA on the Pioneer. And I have no problems using my Pioneer, I've even found that my regulator hits my head a lot less with the tank sitting closer to me. (The reg would hit the upper-back of my neck, rather than the back of my skull if I raise my head up completely)
True, the tank used to wiggle around a bit, but I found that I had to fully deflate the bladder first before slipping in my tank... then adjust the cams. Now I can get it just as secure as when I used to have an STA.
Docmartin is right though, the Eclipse wasn't meant to replace the Pioneer, since the Pioneers still have a smaller profile. The Eclipse is just like a Pioneer with another bag over it. I find the Eclipse kinda bulky actually, since I'm on the small side. I wouldn't mind having one though :lol: