Hydride shifts, generally, will perform 1,2 shifts much faster than alkyl shifts. First, think about the driving force for a 1,2 shift. The driving force is formation of a less substituted carbocation. If you have a secondary carbocation adjacent to a tertiary carbon, and the tertiary C-H migrates, you obtain a (more stable) tertiary carbocation. However if an alkyl group migrates, you obtain an (equally stable) secondary carbocation.

Exceptions can occur. In the lab, there are cases where 1,2- alkyl shifts will happen preferentially, especially in rigid cyclic systems. In rigid, cyclic systems containing a free carbocation the groups likeliest to migrate are those which have their bonds aligned with the empty p-orbital; axial groups, in other words. See the references at the end of the post for some examples.