I did the DDM on my R50 along with some chip tuning and below 4 grand there is not much more than a throaty sound. However, above 4 grand the motor seems to come alive. Pretty narrow power band 4-6k within which to "come alive" but I would do it again. The DDM does seal the box and the cool air from behind the grill is routed into the box. Not a bad setup.
Does Craven sell a CAI for the Cooper? I don't see one. (impulse has an '05 R50)
I like my AFE (have an '02 R50). Fits well, easily installed and sounds great but I can't say anything about actual performance effects. I suspect it represents little improvement in that regard. On the other hand, I haven't bought a new air filter in years. But that aspect won't be an improvement over your drop-in since, I assume, that K&N filter can be cleaned and reused.
If you buy something, make sure you check carefully that it will fit your MINI's model year. The first generation Cooper (R50) was produced through '06 but I'm pretty sure the first gen air box changed shape along with the other changes that came with the '04 "face lift" so aftermarket replacements might also have had to change. Point is, "fits R50" doesn't necessarily work for every part.
Most aftermarket "cold" air intakes are just open element filters that breathe ambient air from the engine bay. Without a tune and probably other changes, the only benefit one will see from an aftermarket intake on a naturally aspirated R50 will be a little more sound.
