The 535s have a very flat frequency response with minimal pinna gain in the 2-4kHz region and a flat bass.
That is a rather unusual response, more common is a lift towards sub bass and a lift at 2-4kHz.
This will give you more clarity and bass, sound much livlier but you should be aware that it is quite different.
Depending on your budget I'd throw in the Sony XBA-N3 which has a smooth, controlled yet detailed mid-treble and a bass that is a bit stronger than neutral but high quality and not on bass head level. (I heard the N3 8 months ago several times, liked it)
A cheaper, more neutral yet also a little brighter option would be the Tin Hifi T4, but I am purely basing this on Crinacle's review, I never heard it.
The JVC FDX1 from Drop is also interesting, smooth and tunable with the 3 included nozzles, from quite bright with the empty nozzle to slightly brigth but smoth neutral with a tasteful, natural mid bass and slightly boosted sub bass. Very good with vocals, very nicely extended but smooth treble. I have the (almost identical) JVC FD02 with mod for 8 months now and like it a lot.
A little cheaper and a little more neutral would be the Sony EX800ST. This one can be bought from Amazon Japan.
Very high quality bass, very natural, fast, clear and punchy. Can be boosted by taping the vent.
Overall detailed, wide stage, a little on the dry side (not that intimate and emotional). Also have this for 8 months, my reference "Studio Monitor" if I want neutral sound signature. (i.e. for Video editing)
I am sure there are many other models out there, it would be best if you could listen to some and try to find a signature that you like, then look for similar IEMs.
