but it depends on your schedule.
We did the 6pm Sat. at the shrine on our first trip. It's only about 15 minutes from the Dolphin (we were at Yacht Club) if you don't get lost. There is a turn onto Vineland that we can NEVER find coming off property. Since we didn't know where we were going, we had left enough time to get lost, double back, ask for directions, and find the shrine coming in from Little Lake Bryan Rd. We got there a bit early, but had a very nice time touring both the shrine and the gift shop there (nice, large gift shop - nothing like it close to home). I only wish that there had a 5pm Mass also, as it is difficult to get back to the Magic Kingdom for the night parade if you're going off season (we were there in Oct.). Mass was about an hour - depends on the priest and the crowd.
Last time, we did the 8am Mass at the Poly. I agree that the Luau Cove is hard to find, but since we knew we didn't know where we were going, we just asked the first cast member we saw for directions and found it no trouble. I was surprised to see that even in the "off season" (2nd week in Dec.) that it was almost SRO. But it was nice to see so many taking time out of their vacation for church. Mass lasted about an hour - they can't go much longer than that since the Protestant service starts at 9:15. Again, I think it took us about 15 minutes to get there, but we were coming from Dixie Landings. If you are not familiar with the roads on property, give yourself some extra time - you can always spend some of it exploring the resort