I'm no expert but I took a look at the two bags you are comparing and they seem to be completely different.  The s82 which is the 9.5" staff bag is just a smaller version of the bigger staff bag.  It has a 3 point harness, full front (for embroidery), pockets are different and in different places on the bag, the 6 way top is lined with what looks like to be a suede material, wear as the midsize bag looks to be lined with a neoprene material.  The midsize bag also only has a strap to carry and the pockets/design is completely different layout. 

the s82 staff bag has the 10" neck and a double ball pocket where the s83 9.5" has only the single ball pocket and smaller neck

I just got the s83 staff bag and it's the best bag I've ever had! When I saw your post I just had to chime in. I've seen both the midsize bag and the s83 and I would definitely recommend the s83. It fits great on any golf cart and fits everything you need for the course including rain gear, beverage pocket, jewelry pocket, etc. Make sure to have Titleist embroider it for you because the pocket doesn't zip off for embroidery later. I love this bag!!

I have the midsize bag and it is a very nice bag too.   I don't think you would go wrong with either one.

awryt man,

how did you get titliest to embroider it for you, did you contact titleist directly or did you buy the bag through a titleist dealer and get them to do it for you?

cheers.

I purchased the bag from Golfsmith by calling in and placing a custom order directly from Titleist. I believe the charge for embroidery was only $15, and you can choose from a few colors.