Yoda is more powerful then Mace, so why the hell did he get the beatdown from Sids...

You seem to forget that sith dont fight fair if Yoda went to get another saber do you thin Sidous would be waiting for him w/o a plan.Sidious commands millions of clones. It was too dangrous to risk.
Yoda knew he had only 1 chance to kill Sidious, loosing his saber meant he failed to destroy him.There was no time for anything else ... Time is a factor.

mm, ok I see what you're saying... and I agree

but the fact is Sidious did destroy Yoda's saber and Yoda had to run... so Sidious won.

And I think that's cheap... Sidious should have handed Yoda his ass.

ah well...