Pros: If it sins it's only by omission
I've searched a bit to find a few cans that work with my lifestyle. Portability is important to me so that rules out lots of great products. I like that the RE0 is low profile, not attracting any attention. The RE0 may be a perfect compromise between sound quality and price. More expensive buds may be more articulate or image spectacularly, but it would be crushing to break or loose them in my day to day roaming around. If these cans sin it is only of omission. To my ears they are quite musical.
I have numerous pairs of Apple's earbuds and I keep a pair in my briefcase, my gym bag and locker, etc, but they leave me longing in two ways. I want more out of the sound because I know it's possible and I want better isolation. The RE0 is a bigger improvement in sound than the price might suggest. If I have a nit to pick it's that I'd like better isolation. Clearly that is subjective and the RE0's come with multiple ends to try. May be some day feeling flush I will pull the trigger on a pair of customs, but until then these work very well.