Personally I'll be trying to switch to mod as fast as I comfortably can. For a few reasons.
• Difference in 17.5 motors is crazy (certified, 1% of the certified, etc)
• Open check books in stock (Mod motors eliminate some of this)
• Even chassis to some extent can be older (again horsepower helps)
• The median driver is more experience (no more getting taken out by the slow guys - I'll be the slower guy. However I am more courteous than others)
Sure there is some reasons I'm not remembering.
Disadvantage is tires. Be going through probably more of them than I do in stock. And losing. I'm not going to be leading any mod race anytime soon not to mention barely anyone runs mod at our local club races.