Anyone out there have them? Recommendations, comments? I am looking for some extra space when traveling on longer trips with the family and these looks like a good idea.

I don't use them, but from what I've seen, they only jold so much.
That means you still have to pack wisely.

That also means you need to be aware of the added height to your vehicle. More important if you park in a garage with low ceilings.
Make sure it's attached securely as you wouldn't want your prized possessions scattered all over the highway, would you?
Lastly, make sure it is locked properly, as you also wouldn't want someone walking off with any important possessions either!

There are also roof rack bags that serve the same purpose, but seem a little bigger than the container items. I wish I had more specific brand info but I drive a pickup, so all my gear goes in the bed of the truck or behind my seat.

Thule work well, you could find one used. Turns a tahoe into a burban. I wish somebody told me to look up, radar domes are expensive!
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I went with a Sears "x-cargo" and it was plenty roomy! Under $200 and held 3 large rolling suitcases and then some.
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A number of years back we got a soft "kangaroo" bag from LL Bean which served us well on my wife's Pathfinder for a lot of trips with kids. After that we always took my 4 door pickup which had the tonneau cover so the bag sat idle a number of years. Then I got my new F150 and opted not to get a tonneau. I Mcguyvered the straps on the kangaroo bag for the bed of the pickup just in case it rains and to keep things out of sight and not blowing around. Though it's not lockable and leaks a little at the zipper, you have to really lean over the side of the bed to see that it's even there.

I have a Thule box that I mount to Yakima crossbars. It's on my Jetta wagon right now for ski season but I'll use it on my wife's Highander for family trips when required.
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