I have used Gobi's on a previous bike but found them just a bit bulky as they have the water res inside plus they weigh more than you would think, I switched over to the Alu Hepco's and they where better IMO.. However I have since gone with Wolfman drybag panniers and will not look back, the extra weight of the Alu/Gobi's v the Dry bags for me isnt worth it unless you want to have the stickered up RTW look..
I do own a Hepco alu topbox that would be used for storing valubles when out on my travels if the situation arises. I am meeting more and more people that are now running softer luggage and most have come from Alu type boxes most are happy to have switched..