I agree with the above to a certain extent, although we know little to nothing about SW8 at this moment. If the budget will not be as high as The Smiler, how low will it be. If it's still above £10 million then we can still see a good ride come out of it. If there's some tech heavy world's first element involved then we can say goodbye to anything decent. It even depends on costs of removing The Flume, groundworks etc. Lets not forget The Smiler's groundworks problems ate up the budget, and Th13teen's drop mechanism ate up that budget. If SW8 doesn't have such problems, and has proper planning and no gimmicks attached, they could get a lot out of a lower budget.
I think all we need to see is a simply good family thrill coaster, with high quality theming. Simply and fun with a unique Towers twist (thematically).