Matt,
The #93 and #89 are really bags for 2 different purposes. I recommend the #93 as a "travel" bag to get you from here to the hotel (then you use your mesh boat bag to go diving and put clean dry gear back in the #93 to go home). It is designed with all the normal compartments of a nice travel bag. The #89, on the other hand, is built to be a gear bag; to handle saltwater (all components which add to the cost) and would be the better bag if you plan to use it more as a dive gear bag (local diving, beach dive, boat diving, or travel as your only bag). There is a reason that some bags cost more than others and in this case it is a set of hardware and components on the #89 that make it much stronger, tougher, and resistant to saltwater. True, you would have to find a way to separate dive gear and clothing in this bag (my recommendation would be the zip-lock type compression bags for clothing).
I should caveat the above to say that you should always clean and dry your gear before putting them back in a bag, no matter what kind of bag, especially if you are going to leave the gear in the bag more than a day or so. If you do put wet gear in a bag, rinse it out with fresh water as soon as possible and hang it upside down to dry before storing it. No matter what kind of bag flush the zippers after every exposure to salt water (it's not corrosion that freezes zippers, its' the build-up of salt crystals in the confined inner space of the zipper.
Both bags have the same rugged wheels. And, both bags have a Protective cover option which I HIGHLY recommend. The cover bags go a long way to prevent airline damage to bags.
Hope that helps. Feel free to call me directly (800-487-9485) if you want to discuss it more.