Round 1: Skincare
Bar soaps tend to get a bad rap as overly drying, because many contain the chemical sodium hydroxide (hence the rule that one should never use bar soap on your face). However, most higher-end bar soaps are just as hydrating as their body wash counterparts, with moisture-rich ingredients like glycerin, aloe vera, and botanical oils. Winner: Draw
Round 2: Hygiene
Some might argue that a bar soap harbors bacteria on its surface—and there’s always the risk that a roommate might use your bar. However, recent studies have shown that there is little risk in washing with a soap bar previously used by someone else.
On the other hand, while shower gels are immune to that occasional mystery hair, the loofahs and wash clothes they require can be prime breeding grounds for bacteria and mold, so frequent and proper cleaning is a must. Winner: Bar Soap
Round 3: Overall Ease of Use
Gotta go with bar soap on this one: Remove from box. Rub on skin. Use until it has completely disappeared. Winner: Bar Soap
Round 4: Travel Friendliness
While bar soap is guaranteed not to explode in your carry-on, plucking a wet bar from your hotel’s shower ledge and packing it in your dopp kit isn’t anyone’s idea of a good time. Travel-size body wash is the way to go. Winner: Body Wash
Round 5: Cost Effectiveness
This depends on the product, of course. But in general, while it's all too easy to squirt out more body wash than you need, a bar soap is at the mercy of shower splash and standing water, which will diminish its size whether you're using it or not. Winner: Body Wash
Round 6: Shower Ledge Space Usage
Bar soap is the only thing that can realistically fit in the specialized bar soap wall unit—it effectively takes up zero space. A big bottle of body wash, however, will monopolize quite a lot of precious real estate. Winner: Bar Soap
Round 7: Usability Near End of Product's Lifespan
The body wash bottle will inevitably be flipped upside down as it approaches empty (and its diminished weight will surely result in a few bathtub tumbles). However, with a little strategic rinsing, you will be able to put every last drop to use. Bar soap, on the other hand, will eventually become a sliver so small it’s nigh-on unusable (unless, of course, you save your slivers and fashion them into a single big soap bar). Winner: Body Wash
In the end, this one is too close to call: It all depends on which of these categories hold the most importance for you. Know what you want, test drive a few, and then go with your gut. Good hunting, gents.