There must be different like 0.1s ? I can live with that. Actually i found this:
"The one advantage to .deb based systems is that the package manager (APT) generally does work faster, since .rpm by nature requires far more meta-data to parse through. Even this margin is narrowing, openSUSE has made some wicked strides with the latest version of zypper."

and

"Both rpm and deb perform similar functions. Rpm has better documentation than deb. Both are equally stable, so no difference there. Which is easier? Depends on what you're used to. Deb is apparently easier to make packages, but harder to maintain."

source: http://forums.opensuse.org/english/o...re-stable.html