IMHO, Radius DDM is tuned not for studio monitoring, it is tuned for "fun", with a lot of airy soundstage which some may say "too wide to be unreal". Studio monitors stick closely to the source and remain as neutral as possible.

Btw, DDM, or other dual dynamic drivers, are new technology which isn't really stable yet. There are durability issues, as this technology may be susceptible to problems compared to single dynamics. I can say DDM is a wonderfully tuned iem to me personally but then, was very disappointed because it broke down too soon (>1 year) and also, I was told that that's the reason why many stores do not carry DDM anymore.

Hence, as good as Sony over DDM, we are talking about two different sound sig. Sorry for sounding defensive, maybe lack of sleep maybe?

At first I was like, go go Sony EX1k,
then i realize, hey, ocharaku... You're from Sony too?
And then... I still wanna try Sony EX1k some day, despite just giving up my EX600 to a very good friend.