The Isles of Glencoe is alright, if nothing special. For some reason they were running a special dinner menu for Rat Racers that was pretty rubbish. But however average it is, it's still a welcome bed for the night. That bus journey back to Nairn is bad enough the day after, can only imagine the misery of being on it straight after the finish.
The trouble is that the bike route is tailor made for a cyclo-x bike. You don't need to be on a MTB for the off-road bit and so it doesn't make a lot of sense to slog up the road section on one. If you can't get access to the right bike then stick the narrowest semi slicks you can get away with on your MTB.