We just bought a Thule hard carrier and so far we like it. We have only used it on one trip but it provided much needed extra storage. DH got it on sale at REI.

If you have a lot of storage space, I recommend a hard carrier, like a Thule. We have one. We probably use it at least 5 times a year, but it is easy to install and take off, adds a lot of storage and has been totally worth the investment. We use it on our Outback, and no, the back hatch does not go all the way up with the carrier on, but it doesn't matter to us, the carrier is still really useful.

I'm looking to get either a bag or hard case for the top of the car. It would be occasional use - maybe 3X a year. Any recommendations or advice?