Originally Posted by wallyx5

Dinan is always very expensive and typical very good. You can not go wrong. But if I were you I would look at Active AutoWerke's tune:
Active Autowerke X6 (TT 4.4) Performance Software -- Active Autowerke Online Store

Or ESS: N63 DirectFlash ECU Performance Software - ESS Tuning | BMW Tuning Parts | BMW Racing, Tuning, Aftermarket, Performance Parts | Engine Power Chips | Performance Upgrades Chip

And not to mention EuroCharged: I have their tune on my M5. Very impressive.
E70 X5