I think there are great points to all sides (low overhead to in-home studios or traveling sales); more validity in client's minds with a storefront, etc. It just depends on your market and your prices - something no one can decide for you.
One day, I'd love to have a studio space - that is my dream. But right now, I'm in between: not quite ready for a studio space, but also not comfortable with Starbucks. I
really, really don't like being the "traveling salesperson" meeting at public spaces trying to pitch my business among the crowds and noise. So, I travel to my client's homes, and they all seem to like the convenience. They are more comfortable on their turf, and they like that I am accomodating. I have a great traveling system down now, and bring samples, my laptop for slideshows, canvases, etc. I set it up while they are getting drinks, etc . Some have invited mom or best friend over too and we just make it a comfortable gathering. It really has worked nicely. It took me a bit to figure out how to comfortably (and efficiently) lug my stuff around, but I finally figured it out.
So I'd say figure out what you are comfortable with. Maybe it means making that leap to have a home office, or move it out of Starbucks and into their home. Either way, if you are booking every meeting, you're doing something right!