Received the AMVR halo strap a few days back and have spent a bit of time with it now.
Was originally planning on writing up some detailed impressions but quite honestly I think this guy covers things well and his impressions align quite closely with my own.
Just to add a few of my own observations on top.
The gasket doesn't seem to fog up very much at all. I did initially wonder if it might be something that AMVR would eventually sell separately, but imho it really needs to be used in conjunction with the halo strap to be usable. Due to the lack of any rigidity (it's just soft silicone) it feels very loose and unstable on the head when used with the standard strap. When the strap is tightened the gasket compresses and results in the lenses contacting my eyeballs long before I can achieve a secure fit.
Light bleed is an issue as the reviewer mentioned. It is limited to the sides and can be mostly be mitigated. But it's a faff and becomes tiresome quite quickly.
I've not tried a halo strap before but personally I feel like the pad on this is too small, sits lower than I would like (presses quite firmly against my forehead) and doesn't really offer much adjustment. Yes, it can be slid backwards or forwards which helps but the angle the pad is mounted to the halo is fixed.
The one aspect thing I do very much like is the rear pad. It's great! Much softer than the stock one and being recessed it removes any nasty hotspots. If there was one accessory that I think AMVR should offer separately, it is this.
After much experimenting I've decided to ditch the halo and gasket. I'm absolutely keeping the rear pad but am now pairing it with the more traditional AMVR facial interface I was previously using. Whilst less glasses friendly (not an issue for me) I find this combo provides a more comfortable and secure secure fit, entirely eliminates any light bleed and find I can hit the sweet spot much easier. Does get a little warmer but you can't win them all!
Don't get me wrong, the halo strap isn't bad. It's actually pretty good but I just feel it could have been even better. Maybe it just wasn't a good match for my head / face shape and others will look on more favourably.