The CRTs are perfectly suited for Hex if you ask me. It's the only ride which could pull then off properly, most likely due to the fact they are so well concealed. The ride doesn't have a "cutting edge" or "modern" image to uphold, like say Oblivion or Sub-Terra. It's meant to be the middle of a construction site (Essentially I'd put that in the same vein as restoration. Hard hats, tools, tarps, scaffold, etc.) so I for one would find it a bit odd walking through and some brand new flat screens being placed around the place. That's just how I see it anyway.
They fit the ride perfectly in this instance, plus I think some of the effect would be lost in the Octagon for example where the video feed is supposed to be interupted. Due to the way CRTs produce light and images they pull off flickering and flashing far better than any LCD/LED/Plasma I've seen.
The water sprays would be great to have reinstated, just to add another sense to the ride. Hex before the vault is all very visual, and aside from the smells there isn't really much which interacts with the riders directly. Bringing back the water could add this to the overall experience, and I think it could be very effective
As for the curtain, like James said it looks a little tatty. It doesn't really billow in the way it used to these days. Adding maybe another thin sheet of material aside, or overlapping the existing one so it flaps around a bit more. I've always thought the existing one looks a bit like it's caught at the bottom. It doesn't really flow out and flap around. More, puffs up
Providing they could lay their hands on a bit of material big enough I doubt it would be that expensive to do. All they'd need is a techie with a ladder to put it up, and possibly move the fan a bit.
I think the ride is looking first rate at the moment in all honestly. We're just looking at the little details which could add to it further