I absolutely love my Shure SE535 Bronze IEMs purchased recently from head-fi-er imackler. In fact, the only thing that keeps them from perfection is their relatively light bass.
I am aware of the filters from mouser one may order (in fact, I ordered several pairs), some of which are to improve bass, but I am reluctant to try them... removal of the current filter may be destructive (ok, not in the hands of a master, but for me!), and there is some talk that the filter to improve the bass also impacts higher frequencies.
It seems to me the Shure SE846 will solve my problem. Its posted frequency response exactly overlays that of the SE535 in all but the bass, which is enhanced.
However, I need to consider other IEMs in the same price range.
Can you report on any experience you have had comparing the Shure SE 535 to either the Sennheiser IE800 or the AKG K3003?