Hi Ben,
If you enjoyed the detail and clarity of the
Etymotic ER-6i's a great replacement would be the
Phonak Audeo Perfect Bass 012. These have the same light and airy attention to detail and dynamics with a little extra power and bottom end. They are definitely not bass monsters but in fact very well balanced - it's all there but presented in a fresh a bright way without being fatiguing.
The
hf5's are brighter, although this is a matter of taste, many sat too bright.