the only reason I could see it being slower is because there are two pipe entries in 5-2 compared to just one in 5-3.

I have been thinking that 5-2 is faster because I (An amateur runner) can get the same IGT as optimal 5-3 and I'm sure top-level runners can do much better than me.

was just wondering if would be faster to find an alternative way over the lava fountains in 8-1 and save time in 8- airship by not getting propeller suit at the start of 8- airship so you can reach the pipe on the first cycle.