Rick, your likely to hear this from most tuning shops as their covering themselves, incase the pods do cause a lean situation.
Every engine is a little different, some may lean out and overheat, some may not. The shop owner can't take that chance on this, hence they recommend the extra items. (Plus the makes more money on the sale.
)
Some EFi Duke owners report no ill problems by just having pods, some also have fitted a tunable ECU of somesort to try and make the most out of it. I fitted pods, but do acknowledge my bike would benefit with re-tune (even though its carbed, its still something to look at).
Pods alone will do nothing for performance, combined with a full exhaust and an ECU will get the best out of your engine, in my opinion. - Chris