My two-pennies... [May contain spoilers]
I look at Sub-Terra as being a little like Hex in the sense that it is more about the storytelling and so on. It isn't all about the ride experience. However, therein lies the biggest flaw. In the queueline you are given very little to go on. They show you a little past documentation of the Nemesis and briefly mention that civilians are now allowed to visit the site - although tbh, it doesn't make that point very clearly.
You get to the ride and the actor-like ride-ops rush you into a formation ready to board a lift with lots of military-esque gusto, barking orders and generally getting away with being nigh on rude to people but tbh, there was no real explanation as to why. I thought perhaps more would be revealed as you move on...
However, it never is. You get on the main ride and it rushes through the whole experience so quickly that you have absolutely no time at all to register what is going on. I guess this might be because they want it to add to the drama and confusion perhaps? As with a lot of ride themes, something goes 'wrong' and all hell breaks loose. When it does it is very hard to tell what the heck is going on. Everyone is screaming and so on as the various effects do their trick but I STILL didn't actually know what the story is and then the next thing you know, you are being rushed off the ride itself and into an exit lift. Only then does the story become slightly clearer as the Nemesis is after you.
Like I say. I think of this a little like Hex. A story based attraction that explains a legend and a throws the ride into the experience. At least with Hex the reasoning behind it all is clear, mainly due to the build up in the queue and the various pre-show rooms. It is almost like they wanted to replicate that kind of experience here but also wanted to keep the queues and overall ride time down and therefore they want you through it as quick as possible. Hex as an attraction does take quite some time to get through, even without a queue so I guess it is understandable but it does have a clear outlining story that is understandable.
Sub-Terra rushes you through the whole experience so quickly that you don't have any time to register what the heck is going on, why you are there and what the story is... Thats why, when you get out and you are getting your bags you just feel incredibly cheated. It is all such a jumbled mess that you didn't have a clue what just went on... And yes, I heard non-enthusiast type folk making similar comments.
The thing is, and I could be off-base with this, but I thought the whole point of Sub-Terra was to better or further explain the Nemesis legend. Apart from the name of the ride and a brief mention in the queueline (its actually a clip of the original promo video with the scientist and woman reading the book) there is very little that ties this to Nemesis at all.
Overall I think the concept was a very good one. I would even go so far as to say that it has the potential to be fantastic. Everything looks the part and the fundemental stuff is there. It is like an action film that has been edited down to only the final action sequence. (Which in theory sounds like a reasonable notion, considering some of the action movies out there
) It is just that the 'pacing' is all off. As I say, the fundemental stuff is there but the story is lacking and rushed which is detrimental to the overall experience. I agree with Marc that they can't change the ride system itself, however, they could make the overall experience far better with a little more explanation in the queue-line videos and perhaps an extra video when you are waiting to board the first lift perhaps. As it stands, it is a poor attempt at a sensory experience, but adjustments could be made to make it a whole lot better...
I kind of like it because I can see where they trying to go with it and I appreciate the issues they have to contend with. It is not an awful attraction. It is mildly enjoyable. Whether you will ever wish to re-ride is another matter though.