Although slightly off topic, thought I should just mention it. Saw is actually 35 feet taller that Oblivion (so add half of the visible oblivion drop on top of it), although Oblivion has a much larger drop
but unless I am very much mistaken, its the drop that people are going on Oblivion for, rather than the over all height of either coaster.
In terms of comparing the two, it's a very odd mix because although they both have 'the big drops' they are completely different in every way. Saw was designed to fit a specific market for Thorpe Park much like Oblivion was designed for Alton Towers. Each pull off their signature feel very well (in my opinion) and so they should remain that way.
obviously Saw benefits from being able to use its theme alot more, its more recongiseable, and as I said, its even got more time, including on the Coaster to sell it.
I can see what you mean about the ride being short, however when queues barely tickle 20 minutes you can't really complain!
I dont know if the fact it has a short que, is such a good thing, certainly not if that is down to the amount of people going on it, I do recall the early advertising being focused on the drop, I just wonder after 18 years, that one element hasnt gotten old.
Stronger themeing will help of course, but I think it needs more than that, maybe a 2nd but smaller drop back underground, one more hidden away, which shocks riders, ala 13. (the surprise element, not how the train drops)