Talking about bricks, presumably there must be some way to get the firmware reinstalled in the event of a glitch?

Yes sir there is, via windows explorer if it's not totally dead-

the problems I have had have been discussed reasonably regularly on the Garmin forums

I have the 590lm with a sd card and I traveled with it in Europe, Canada, Alaska USA and Latin Amerika.
Didn´t had any issues, when you just swap cards for the big countries. As I guess you can download pretty much all African countries you travel as there a not so many roads anyway.

I wouldn´t get the 700i as it costs a lot of money and basically does the same as the old once. All the gimmicky features you won´t/can´t use in Africa anyway.

GPS Garmin 700i
 

Hello, I hope you have an AMAZING TRIP.
I am preparing for my first Leg of my RTW trip, and am considering USED older vs. 700i Montana.

One Note to consider.. I have found online true LOCKING brackets.. so Its vertualy impossible to steal off the bike, without the special, tool, and or they steal the entire bike,., But very easily removed if shopping, or Overnight.. etc. :funmeterno:

Is it a download from Garmin, or do you have to copy your uncorrupted drive contents to your PC as a precaution/backup then copy them back in if it bricks?

The 700 series is a HUUUUUGGGGGEEEE improvement over the 600 series but if you've already got the 600 stay with it. Ive recently done my first 16k km with the new 700i and it is fantastic.

I bought the 700i and I agree it's much better than my old 610. Screen is significantly bigger and it's nice to build the InReach functionality into the GPS. You can pair with your phone by Bluetooth so even if you can't physically reach the unit in event of an accident you can still send a signal.

I did have some software problems on the 700i initially but they changed it under warranty and the replacement is mint :)

I've kept the 610 as it's not worth much now, and I'll probably put that on my runaround bike.