We just got back from WDW, our first trip there. We went to DLR last in 2010. I must say, while we loved WDW, we prefer
Disneyland's magic kingdom over WDW. AK, DHS and Epcot are a whole different story.
I don't know if Indy and Dinosaur can really be compared. We liked Dinosaur, but once you've been on it, it's not a ride that makes you want to run back to the line to go again. We've ridden Indy multiple times in a day on more than one occasion. It jostles you around a bit, but it's a fun ride.
The Matterhorn is a great rollercoaster, again a bit jostly, but not super scary, like someone else said, about on par with WDW's Space Mountain (and again as someone else said, Space Mountain at DLR is much smoother, I like it much better there). Big Thunder Mountain was closed for refurbishment when we were at WDW, so I can't compare.
If you've never been to DLR I have to tell you to make sure to ride Pirates of the Caribbean. It is IMMENSELY better at DLR. The ride is twice as long and has more interesting elements. I also recommend having lunch or dinner at the Blue Bayou where you can watch the ride boats go by.
I miss DLR, and want to go back so much! We're going back to WDW on our next trip in spring 2013, but I'm going to try to set up a special trip for my birthday in the summer at DLR.