Eddy,
So far I've launched locally, within 5 minutes to a half hour from home. I'm fortunate to live on the coast, and there's plenty of launch spots minutes from home.
Regarding stability of the Oasis on the roof, I've driven over 65 and it doesn't budge, absolutely rock solid set up. That being said, Pat at Jersey Paddler in Brick NJ showed me how to properly secure and lash my straps to my rack and how to secure the front and rear bumper lines.
For me, the Thule Hullavator for me is a perfect solution for this big yak. It's an amazing design that allows me to take this yak by myself where and when I want to go. Here's a link with reviews, I rate a 10 out of 10.
http://www.paddling.net/Reviews/showRev ... od=1565#sf. It isn't cheap, about $500-$600, but for me, worth every penny. Like almost evrything, you have to shop around. The rack for your vehicle has to be compatible as well.
I'll be taking a trip to Virginia Beach soon, and since thats about a six hour drive, I'll put the yak "upside down on the roof vs. the way you see it in the picture. That will be much more fuel efficient I'm told, and you don't want to store or transport the kayak like I have in these pictures for any real distance to avoid causing any deformation and "dents" to the hull. The top rails of the yak are much stronger, and they won't deform. Dents however can be pretty easily removed. Regardless of the yak you decide on, I found that the Turbo fins have made a big difference for me, allowing for faster speed and I can cover greater distances. An expense well worth it IMO.
I'm not a small guy either, 270lbs., but I'm getting older, 55. The Oasis is a big and pretty heavy kayak so some thought has to go into soloing an Oasis. Additional grip handles, ballast bag, a rack system that works for you and you've got a fast, stable and very capable, and a real battleship of a yak in the Hobie Oasis.
Let us know what you decided on.