DaveCoRight or left? I can't tell either and Bad oversight on Sennheisers end. I have to play a left channel pink noise tone to tell. Not all have that with them in portable situations. I got the CX 1.00 (60% chance), So no luck for me. The CX 1.00 is fairly neutral sounding and not very efficient. You have to use the right ear silicone size and insure they are pushed in enough to form a seal. Decent bass and extension when done so. The mids are bit lacking and not that clear but overall sound is better than I expected. Good definition on the lower bass and a pleasant treble range and detail. I am not much of a IEM fan so likely I will not use these much. Neutral is hard to find in a headphone though. I do not even find the AKG7XX neutral enough for me.
Maybe I will try the 5.00's one day.