either one will do nicely.
You'll find that competition are gaining in popularity as they seem to yield slightly better performance. The button is lighter action and is a bit faster. Some also like the fact that it's a good button to mash on for quick presses.... Happ is currently selling them for $.10 less also.
Ultimates are good but just more traditional. Sometimes they go on sale. The other month, they were $.99 each so I bought a mess of them.