So how do you decide on your stem length. I have what came on the bike. People said since it had Phil Collins.....wait,that isn't right. Maybe Mike Rutherf.....no,no It must be Peter Gabriel, maybe Tony Banks geometry, then you had.....oh crap. Now I remember. It's Genesis Geometry( I must have had some misunderstanding ) But seriously , do I need to stay with a longer stem, or can I go shorter. I have seen folks running shorter stems, and when I see POV videos, it gives the impression of better control.

I have nothing to add other than the fact that I appreciate your 80's musical references... 

Seriously though, My X-cal came with a 105mm stem and I always felt too stretched out.  A friend let me try out a 90mm stem he had laying around, and the benefits were immediately noticeable.    I felt much more in control and confident maneuvering my way through turns.  I always felt in the past like I was trying to turn a school bus.  The shorter stem made the bike feel much more responsive.  I'm a fan and will keep the 90mm stem on.