Front is by far the best, and I would rather wait a little longer for front on Smiler than any other ride on park.
They have certainly been doing something with the wheels, as on Monday the trains were louder than Nemesis and it was fairly unpleasant queuing under them. However by Wednesday they were a lot quieter and not so noticeable. The wheel covers were sat in the maintenance building on Wednesday as you could see them if you looked across on the break run.
Its good to see train 3 going around now, that was still sat on the switch track wrapped up on Wednesday.