I was wondering this myself..
After pulling this FI system apart, I've realized that it's not as bad as I thought it would be, but still, carbs seem to have less problems and cheaper upgrades. Plus, coming off dirtbikes, I don't mind tuning carbs (actually, I like it). To increase the flow of an FI you need to change MAF, TB, Injectors, cold air intake and think about another computer. To get better flow with carbs, slap on the next size up and rig some linkage (i think... could be wrong, but this seems to be what I have read). Also, I don't need to worry about emissions here in Canada. Do you carb guys further north have to re-tune when the temperature drops for the winter?