Wally West was more interesting, because when he replaced Barry, he couldn't run faster than the speed of sound, he had limited stamina, and had to eat 20,000 tacos to power up. Low blood sugar was his Kryptonite. Then they had the issue where he learned how to untap his power, and it all became FUBAR from there.
If you look at the absurdity of the speed force, it grants:
- the ability to run through time
- the ability to regenerate like Wolverine
- the ability to draw mass and super strength
- the ability to become intangible
- the ability to deny people velocity, freezing them in place for an undetermined time
- the ability to run through time
- the ability to freeze molecules and create super dense objects
- the ability to stop aging
- ability to punch at FTL speeds (atomizing anything in front)
- the ability to have an invisibile forcefield on at all times, but it scales directly with speed
- ability to whatever the hell else is in the speed force at the time
I'm sure there's more, but pretty much, a guy like Wally West can reach into the speed force, and grab whatever ability he needs at the time. Talk about deus ex machina.