Unfortunately, TT bags are hard to locate to check out. The difference in the Streetwalker and the Pro are actually pretty minimal. The SW Hard Drive is too much for me but the added room in the Pro is nice to have. I don't carry everything all the time - just what I need. However, when it's really loaded up, the extra space is welcome and the bag is just as easy to work with.I'm considering the Streetwalker, not the pro. I think the Pro might be a tad bigger than what I am looking for. I stopped by B&H over the weekend, but they don't carry TT, so have to go someplace else to check it out.
Excellent quality from TT, regardless which product you choose.