Same conclusion here after tested some grills mods.
Without grills, or slight grill -> Good soundstage but less bass response.
With stock screen (removed foam) -> Slightly less soundstage but better bass response. So I stay on this one
i found a vast difference in soundstage size. It was like a 135 degree vista with a couple of thick posts at the front corners to a 210 degree view with no posts. Also some reverb noted in the lower mids and upper bass with the screens was removed. If I didn't have a hammer for an amp the lack of bass might irritate me, but any trace of midbass and upper bass thickness is also long gone with no screens.
Listened to some HE-6's (orig) yesterday at one point on a WOO WA5, the 500 is so similar. Lacking some treble details, but also the HE-6 has a harder more angular treble, didn't listen to enough bass stuff to see how much it had over the 500, but the point is the 500 is a heck of a can.
Off topic:
Yesterday in the "affordable class" it was:
1 Voce
.
2. Shangr-la
.
At a higher price (much) the Shangri-la had the HE-6 beat in many ways (not moving as much air in the bass was the shortcoming). Better than that to my taste was the Voce. Coherence to die for. From 30Hz-~11 KHz I'm quite sure I've near heard it's equal (never heard the 009). It doesn't make detail the only pursuit, there is a musical liquid gentleness that is instantly addictive.
.
3. HE6 (orig, no mods) potent across the board, highs could be hard, but the detail is intense, and it runs all over everything under #3.
.
. (call me a liar but I'd rather stick with my modded HE-500's than any of the below cans
.
4. Senn 800 - missing bass, clinical. Big soundstage, but the sound is like a great painter that paints in hyper realism, realer than real, with missing organic and harmonic pieces. A fave among Robots and Dieter.
5. Mr Speakers Ether Flow C (surprising finish) - fun and gusto, a bit tipped up, row B
.
6. Ananda - forward, lacking depth and body
7. LCD3 - better than the 2C, relaxing perhaps addictive to some - but still with the missing 12kHz and up, and laid back upper mids, and overly thumping bass. Easier listen then the Ananda, but less accurate. Where it is good, it's good. Can be lush and can push the bass, then I want to hear the high notes and overtone and it goes flat and dry.
.
8. Mr S Aeon Open & Closed - forgettable in this company, where is the soundstage?