IMO it really depends on your individual definition of adventure & just how much maintenece you're willing to put up with.
The rfs isn't an LC4. A LC4 isn't an LC8. They're all built for different purposes & they all have different lifespans.
The real question you need to ask yourself is what's your purpose?
BTW- could we all stop using the Paris/Dakar rally as some form of "gold standard" to judge the long term adventure "worthiness" of any particular ride? In case we don't realize it, the bikes are purpose built for the event & disposed of afterwards. Look no further
(bikes were pictured earlier in this thread) They built a couple of '05's for the 2006, then did they pull them out of the garage for '07? NO! They built a couple of 06's, & so it goes with racing.
Just because something can be extensively modified to work for 5000 miles, doesn't make it a great candidate for a long range/long term, adventure bike. Look at the number of rfs based bikes that didn't finish event.
Having ranted a bit, I'd love to have a EXC for some short range fun