105 is a stronger compound and will cut faster, but the work time is limited to around 3 passes in my experience. To combat this I use a detail spray on the pad along with it, and that seems to remedy it most of the time. Keep in mind though, SIP will leave a nicer finish after use than 105 will, but both will most of the time require a finer polish regardless depending on that pad used.
E90 ZCP Alpine White M3- Gone
F82 Azurite Black M4- Current