The Killer Mask is about the same as Hero Sharks for vision: the little dot shadows it creates in your view never quite disappear, but taken as a whole your vision is less 'greyed out' than using the smaller hole perforated sheet mesh which does disappear from your view quite quickly. I'd say it's fine for CQB, urban, or semi-urban sites, but either small or large hole types of perforated sheet interfere with spotting camouflaged people amongst foliage at a distance.
With small holes it's ok in bright sunshine, in fact they work like shades so they can make spotting people easier, because you can stare at brightly lit areas for longer and give your brain chance to distinguish camouflage fabric from the natural colour mix, but not so good in mixed shade woodland. That said, smoked lenses are just as much of a ball ache in shady woodland - great for the brightly lit patches, but then you're momentarily blind when you look into shadow. But anyway, large hole perforated sheet like in these killer masks doesn't work in the same way. I suspect it has to do with polarisation - as somebody said in the recent fog thread, small hole perforated sheet prevents light from wider angles getting to your eye, but when the holes are larger it doesn't work like that so much. The best mesh is interwoven wire.
The bloke who makes those ballistic lenses for S10 respirators is a member here, but he doesn't post anymore:
Blueangelical, which is also his fleabay handle iirc. I don't know what respirators you've tried SBR, but S10's don't fog and they're not that sweaty either. That of course assumes that i. nobody has messed with the internal structure and ii. it is the right size for your head (1-4). The way the interior works draws fresh air across your eyes with each breath. I have been shot with the original lenses, before i knew that they are not ballistic rated, and it didn't crack, but I have no way to know what FPS or BB weight it was, just that it would have been within Skirmish's site limits of 368FPS for AEG's or pistols and, at the time, 500 for both semi-auto and BASR's. It wasn't point blank though, just a normal skirmishing hit... I wouldn't recommend using them without swapping out for ballistic lenses however.
Dunno if you noticed the size of those bandages above, SBR? 1 each 20x19cm and 10x19cm - pretty OTT, but I could do 2 of the larger ones if you prefer. I have also remembered I've got an unused 25ml tube of fake blood (I had a similar idea, but I'm more into my Soviet loadouts now so it's surplus). Now the mask doesn't need work and with the fake blood = £17.50 posted.