Definitely Tink! I ran both this year and enjoyed the Tink course so much more. There were less people so that was a big plus (Princess was WAY too crowded for me!). I also liked that we were in the parks for almost 6 miles for Tink versus about 2.5 for Princess. The weather was definitely better at DL too -- no humidity!
I did like that there were characters throughout the entire course at Princess, since its all on Disney property. But running through Anaheim was pretty cool too
And the expo for Tink was MUCH better organized! Of course, that may be because Princess was at Coranado this year instead of at the WWoS...