All things being equal.. In general which is better to start off ranking for your keywords. I have a choice.. which would you pick? 1) Brand New URL with your keywords in the domain 2) >PR3 domain with very little indexed content if any-- no keywords in domain 3) Aged domain with very little indexed content if any-- no keywords in domain.
I would actually start out fresh by choosing the brand new URL since you have great potential... Although I believe the PR3 domain would rank the best.
Age is a factor considered by Google...but that alone is not enough......you still need all the other stuff....
On page content + age only accounts for 10% of your ranking. PR3 would rank better I believe, but still go with new domain cause its worth more and its ranks very well too.
I'd do 1) Brand New URL with your keywords in the domain you can always boost your own seo scores. look at the future.