I didn't personally find it excessively rough back at the start of August mind, but I did realise the whole shock that it's not even been half a year...
Whether or not it's up to the same levels of Saw, I cannot say yet... Saw was bearly rideable for me in it's first season, so it's all going into personal opinions here... Then again, with the heavy amount of work the cars have to go through on a daily basis, it can't be that big a surprise that they're wearing down a lot faster compared to other rides... Hell, it probably does a lot more work than Nemmie does... But that can't be compared since B&M actually think through their designs...
It's a weird one how the two Merlin Gerstlauers are quite bad for roughness, as even Mystery Mine with it's set-square corners isn't awful...