I went through a DE at Watkins Glen with my C4. Asked around if the C4 should help or hurt re: handling at high speeds, etc... one reply was that while the C4 should handle the curves better, the extra weight negates any advantage... better reply was that I would definitely have an advantage getting back on the pavement if/when I "go agricultural".
Good Luck,
P.s. Tim's 2004 is a great deal. Check it out.