Russ,

I have used both Landwehr and ARR preamps for 2 meter SSB. One of the
major issues is how much coax, and what quality, you have. Another is
the quality of the preamp which you have in your rig. In my case, I
have about 70' of very low loss coax, almost hard line in performance.
The preamp in my rig is fairly good, and the result is that there is
little difference in performance, though there is a slight nod to the
mast mounted unit. Lossy coax would definitely tip the choice to the
mast mount. And in fact, on 70 cms with equivalent components, the
mast mount is the clear winner. Beware of units which don't give you
noise figures, as that is normally much more important for weak signal
work than gain.

--
Alan
WA4SCA