Fast Shmups? (either in scrolling speed or maneuverability)

[Gespenst]

^YES. How'd I forget that, RS' Stage 3 intro is one of my favourite scenes in the whole genre. You get a real sense of rushing over the water at low altitude, and chaining those speeding gunboats is intense. I love how the ship slows down and ascends once you reach the dam area, too.

And don't forget the highway speedrun in stage 7, too.
BTW, IMO, Raiden III can be considered a fast shump too sometimes. (especially in final stage evem with slow moving ship)

- Speed up level in Gradius games.

Especially in Gradius Gaiden. I love the moment when fighting Boost Core

[Chacranajxy]

I kinda want to say Soukyugurentai. Every time I switch from another shmup to that one, I feel my ship is a'zoomin'. The backgrounds don't scroll all that fast, save for in stage 3, but it does feel pretty damn speedy the whole way through.

[BIL]

Having been playing R-Type Delta for the last couple of days, it bears mentioning here too (maneuverabilty-wise). The speed control is perfect; 1 for pixel-perfect bullet milking, 4 for crossing the screen in a second, 2/3 for everything in between. Best of both worlds when you're zipping from one high-risk scoring trick to another.