I'm a long time ER4S user (been thru 3 pairs now) and no the Roxanne is nothing like the Etys. If you like thumping bass, you won't ever been satisfied with ER4S even if you implement them into your canal. Having said that, I'm not really a bass head and sound signature wise I do prefer the Etys over that of the Roxanne. The discomfort (well, an understatement) of properly wearing the ER4S is really the biggest barrier and even after a decade I'm still bothered by using it any longer than say an hour continuously. I had also tried remolding the Etys into custom shell but it changed the sound so significantly I had to re-buy another pair to use. I also tried the canal works CW-L05QD which put 4 of the er4 BAs on each side but nope, I find it sound worse - more is not better than less. I'm a bit perplexed since when we had collectively (me included) fall for spec marketing where price/# of drivers/tech jargons became an "objective ranking/classification" system of quality and anyone who suggest he/she may prefer a "cheaper/lesser/inferior" product is being frown upon.
I like the Roxanne, I think it really aim for those who need more bass and higher volume as it does these very very well. It never become shouty or grained when I push the volume up. Personally I don't use them loud and like more treble presence so for me I'd prefer the JH13fp to the Roxanne.
ER4S really is a classic performer. I remember (I think it was actually kkcc) who told me:
"Whatever IEM you ever own your ER4S will always return to impress you"
I found that statement quite true and share it with others. Like anything the Ety won't be for everyone though it's stand against the test of "audio years" says it all really.