I would like to point out that we should give Alton Towers a good few weeks to tamper with the improved Sub-Terra. Much like the original version and any other dark rides upon opening there will always be things that need tweaking or adjusting until the experience is 'spot on'.
Alton Towers will have no idea of how the product will work with the public so it does take a while to make little adjustments until you end up with a spot on dark ride. Hex being a prime example.
Just saying that before we get the herd of 'omg Sub-Terra is crap' posts surging in. These things take time people.