What do you mean by point-to-point?
Point-to-Point as in a straight line not involving roads?
or just Point-to-Point as in "take me from this point to that point without me thinking of it"?
First of all, go Garmin. They're just the best. On AdvRider in Parallell Universe there's a huge thread about GPS' on F800GS, and there's only a few non-Garmins on show.
Onwards...
Most cheap SatNavs - in-car type ones - have very little concept of the world outside of roads. They're pretty useless for even the slightest trail. You can't even get your lat/long on some of them.

(Think Garmin i3). However, they're very adequate for the road.
If you want a GPS (vs. SatNav

) you'll usually get strange farkles like fishing calendar

. However, they really don't want to supply road-maps with them. If you get say Garmins City Navigator, which will cost you, they will do turn-by-turn road navigation. Some of them don't have the capacity though, so look for one with a memory card slot if you want this.
My choice is a Garmin eTrex Legend HCx (those letters are important). It runs off two AA-batteries for 30h, it's tiny (pocketable), it's advanced enought to not be dumb, but still dumb enough to do turn-by-turn navigation (with additional maps

).
It's mounted on my bike with RAM Mounts, and a cheap, butchered, USB cigarrette lighter power supply is powering it.
My girlfriend has got an old Garmin i3 - and it's
very dumb,
very. However, it's small, cheap and does turn-by-turn navigation. She's also got a newer Nüvi and that's fast, pretty dumb, but still advanced enough to be useable on a motorbike. She's got that one mounted on her F800GS with, again, RAM Mounts and powering it from a butchered USB cigarrette lighter power supply. neither of those are waterproof, so keep a plastic bag with you, or stick it in the pocket when it's raining.
If you're on the cheap, you might find that two used old Garmins migth be the cheapest option. Something like an i3 for road navigation and an eTrex for off-road. Mount them with a RAM Mount.
Hope that adds to the confusion.
