I have both the ref2 and the 104's. The ref2's have a better high end, cymbals "sparkle" and guitar strings "tingle". The mid's are strong and the base is very nice to my ears, but I have never liked a booming base.
The 104's have an equally good mid range and a some what more "bloom" in the low end. The high end is excellent, but lacks the "tingle" that the ref2's have. Sorry about all the quotes, but it is hard to put listening impressions in words that are not flowery. The bottom line is that both speakers are excellent, but the ref2's are in my listening room, and the 104's are in the living room. I have tried both speakers with the same equipment in the same room for extended periods.