Warpath is great, but sometimes it can be hectic. Spies have to work a lot since there isn't that much room among the whizzing bullets and explosives to maneuver. But, I found that the backstabs I did get were very rewarding. Being a medic is great since you get to be on the front lines, and medics are especially useful because it allows heavies and soldiers to be the most effective. Especially in taking out those sentries. Once there was a group of four medics healing each other and working to save everyone on the front lines. We survived (or at least I did) for a decent amount of time. Seeing this level of teamwork and communication is very rewarding to me.
I was playing on warpath yesterday and I did meet some very nice people. Some were in the clan, some were not. There was this one guy that wasn't in the clan who was a sniper and requested an uber. Just for the fun of it, I ubered him and he ran out there with his machete. It was pretty funny even though in the future I recommend medics using their ubers on heavies, soldiers, and pyros.
And yes, I too will accept your challenge.