I'm a UK eTrex Vista HCx user running BaseCamp on Mac OS X. I recently installed the Topo GB from disc onto the Mac and also onto the eTrex. I was surprised to see that the OSGB map information had been 'translated' into US Topo map colouring.
I found this disorientating, as I am used to the symbols and colour coding for the OSGB 1:50000 and 1:25000 maps, and it was not straightforward to use the eTrex with regular paper OSGB maps. I wonder if other non-US users have found this an issue?
Thankfully there _is_ an option to display the coordinates in OSGB format.
(apologies -- I'm sure this is not a Mac specific issue, but I couldn't find an appropriate section in the forum to post this.)
Sayling