If I was more into cruisers, the Rocket3 would defenitively be on my list, its an awesome bike!!
That being said, the reason I chose the GSA was the versatility of the bike! I'm the curious type and I like to be able to go check what is at the end of that particular road whenever I can, that it be paved, dirt, some old wagon road or even a four wheeler path, the GSA or the GS can get me there! Sitting high on a bike is also a plus for me as you see better!
I would look at what you plan to do with the bike and go from there!
Ah ya!, One more thing, the GSA looks good clean or dirty, another plus!!
Good luck with your decision, I'm sure you'll love either one!