My experience is that the MS4 is significantly better than the Helicon 400 and the MS5 is significantly better than the MS4. I owned the MS4 and replaced them with the MS5. I sold the MS4 to a friend who had the Helicon 400. Have not heard that Revel model, but my Dali comments are based on same system direct comparison.
Revel F-208 versus Dali Euphonia MS 5
Any thoughts on these two speakers I currently have the F-208's But am considering the Dali's because in my past experience with the Dali Helicon 400's they have a huge sound stage and really tight bottom end Thanks for your thoughts