Race vs Sixdays

[southbound]

I am buying a new bike for a two day desert race. After that race the bike will be used primarily in tight woods that are laced with roots and littered with rocks. My dealer is recommending I buy the Race model because it will do better in the desert than the Sixdays.

What are your thoughts on the Race model in the deep woods (Here at home it's first and second gear, almost trials like).