I would be up for this, I think the results might be revealing.
Although I would have thought we'd used the wizard, thats traditionally the class thats bemoaned about. I suspect you picked the druid because there are problems with the druid in 3.x, which recieved so much needed attention in pathfinder.
What I find a problem is when people argue that the magic/vancian system is incompatible with the at will fighter. A better therefore would be either a 3.x wizard vs fighter, or a druid vs fighter from pathfinder.
I picked the Druid because the statement was 'the 3.X fighter was not invalidated by the other classes.' Not the Wizard. The Wizard breaks the game in amazing and fascinating ways, but as a solo party member these ways become less apparent. For instance, Stinking Cloud can disable an entire group of enemies, to be picked off at whim. But... how does the Wizard pick them off? He either expends precious spells, or asks someone else to do it. In this manner a Wizard and a Fighter together can kill 4 fighters with ease, and do it all day long. But a Wizard alone would have to expend most of his spells to just do the volume of damage needed to kill the fighters.
The Druid, on the other hand, not only can disable all 4 fighters with ease, he can then kill them with ease.
Spellcaster versus fighter - the best PHB class versus the... well... not the worst (MONK SAY HI) but pretty bad.
Also, I love Druids, and know them like the back of my hand. I played Druids in AD&D and 3E, and when 3.5 came out it was like... say what? You took a class that was powerful and flexible and removed every limitation on the power and flexibility. It makes it very easy for me to design a character for this test, whereas I would have to look through a bunch of stuff for the wizard (thematically, I don't really like Wizards. Irritating bookworms with superiority complexes).
P.S. I don't really care for Pathfinder. I played it once, it didn't really do much for me. So I'm not really going to try to do anything with their rules, I don't know jack about them.