Exhaust and the V8 to V4 mode

So, I was talking to my friend who is the head Tech director at Magnaflow out here in Southern California. Asked him about the Magnaflow cat back for my 2007 Tahoe...he said they have sold over 300 kits nationwide already, says they have been getting great reviews (which I have also seen from members here and other forums). He did say that one common "complaint", or comment, is that when the Displacement on Demand feature kicks in, and the motor goes to V4 operation, that the exhaust tone sounds "weird"...not a Honda rice burner type noise, but kind of a boxer-four-ish type noise...definitely not V8 rumble.

So, can anyone comment on this? Is it noticeable in everyday cruising? does it sound BAD? Or just different? I'll be honest, the V4 mode doesn't kick in all that much when I am driving, usually only when I am coasting actually...so not sure it would happen all that often?

I know I have to get some kind of cat back for this truck, it just sounds too wussy for me (I do love the quiet ride, but I need a little V8 rumble)...so any comments/suggestions would be great. I've always had Flowmasters on my other vehicles (latest were '02 Z28 and '04 GTO), but I don't want THAT much interior resonance in the big SUV...

Thanks...also, best places to buy? Average price for the system?

Although I haven't put my GM cat-back exhaust on yet, I'm guessing that since you only get V4 mode is when you are going down hill or coasting, it won't be that noticeable. I can tell a very slight change with the stock exhaust.