I already own a DK2, and tried the Vive at EGX on Thursday in the HTC booth rooms (so not the Frontier ones)- I was hoping to see a different demo for the HTC one and then try the Frontier one later, but ED was really being pushed as the premier experience (no bad thing of course), but I was hoping to see something like the Portal 2 Vive demo for this to see something brighter for comparison, but hay-ho.
So, I met a chap called Aaron (I think) from Frontier, but time was really limited so I only got five minutes to try things. There was actually a small technical issue at the time- the headset needed calibrating "again" (so he said) as I noticed a blue box sitting above me whilst I was flying around- apparently this is the grid you'd see when you reach the limits of room you're in. I had to therefore ignore this floating blue box (think Star Trek holodeck) as time was pressing for others outside (it was busy!). I found it odd that this had happened at all- this was obviously a sitting experience, as I got to see in the blacked out room the two units that are set up to map the room out, and I had to sit down on a seat with an X52 Pro in front (so no moving around for this sadly!).
The text is much clearer than the DK2, although it still is pixelated a little. The headset felt a little lighter and certainly fitted to the face was more comfortable than the Rift, although obviously nobody has tried any release products to make a fair comparison!
So, certainly no real screen door, and no stutter although as I suspected it would be, this was just the Training Scenarios we've all got already. My personal opinion on the stuttering is network latency to the Amazon servers, so the fact I experienced none was to be expected, but I reckon that probably hadn't gone away for us completely.
I asked about the hardware specs and he wasn't sure (some equipment is loaned by EGX so I'd been told later), and I asked about whether SteamVR required the game to be running under Steam at the time and he'd already left the room whilst I was playing, and I wished I could have had more time to probe further! The thing is, both my friend and myself got separate booths to try things out, and time meant we couldn't have a good look around the menus or change any options- the demo person also had a screen and were controlling the menus to get us in and out of those scenarios.
Personally, I prefer the Vive, but who knows how the Oculus CV1 will compare. However, I will buy one of these anyway, as I can't see SteamVR integration from failing to produce some great titles. Oculus seem to be standing still- HTC Vive was all over the place at EGX!