Two different beasts. I haven't really heard any IEM that can beat RE272 on detail retrieval, and its soundstage is rather good for an analytical sound. RE600 in comparison has almost the opposite sound. Instead of focusing on being analytical and more or less sterile like RE272, RE600 is liquid and musical. The main focus is on the mid and bass. Soundstage is obviously small because of its forwardness but it has a fairly 3D quality in it. It is more enveloping than it is open-ended.
I won't say one will trump the other on everything since they both have their own strengths. You can call it a sidegrade but to me the comparison itself is apple and orange.
Sound like you are describing BA200 to me. Hopefully you will like it.