HF5 isn't as bad as the ER4 in terms of microphonics and can be worn over-the-ear much more easily. The W1 has no microphonics but a very different sound signature. Its sole strength is the warm and transparent midrange but it doesn't have the range or articulation of the Ety single BAs. Ultimately it's up to you - do you want to depart from the Ety signature for gains in usability or stick it out with the Ety sound? The W2 would be a best-of-both-worlds sort of thing but obviously it's much more expensive.
