Hardest Class to play?

From what I've seen and read from people on TF2 forums I see how everyone calls the Pyro a lower tier class, with a reletively easy way to kill people. Just hold onto a button when your near ppl and there dead. But it's much more complicated then that as a Pyro dies to almost every class when they see him. When I play Pyro though and what other people have experienced I'm sure is that when they do flank and blaze the enemy Soldier or Heavy the enemy just turns around and kills you, while their health barely looks damaged. So my question is this, "Is the Pyro the hardest class to play effectively without constantly dying?"

a great pyro would use resources other than his weapons to be a major factor. the flamethrower is pretty much a melee weapon if you think about it. i always see pyro's as just a distraction because they are the best counter for spies but a wicked demoman or soldier can also do the pyro's job.

The pyro should only pop out when he is least expected: ie the other team is focused on fighting on a battlefront, while you sneak up behind them, similar to the spy.  The disadvantage the pyro has versus the spy is that he cant turn invisible, but on the flip side he is a great medic buddy, especially in defense, which the spy is not.

I would say from playing that the Pyro is indeed one of, if not the toughest class to master; with Spy and Sniper being high up on the list IMO. I think the main thing people don't get with the Pyro is the fact that it's intended to be an ambusher, hit and run style of play; with a major role being to constantly harass the other team and disposing of lone enemies. In a lot of situations, a Pyro can really disrupt an objective. Even if the enemy doesn't die they basically need to stop what they're doing and find something to put out the flames, and a good Pyro will try to gobble up all the medkits in sight to make it tougher. If you want a good idea of the basics of the Pyro; I reccomend watching EvilDaedalus' how to video on the class (check Youtube or the like), and it should be able to help you out.

I've seen the videos, and I know the class effectively enough to use him. What I was saying is that the difficulty about the Pyro is that even when his job is to find Spies and generally cause chaos it can be a suicide attempt and the aftermath can be cured if theres a medic hanging around, that's why his class his hard to play. Ambush or not he can still get killed as the flamer seems way too weak to kill of Soldiers and Heavies quick enough for them to realize theres a pesky Pyro behind them flaming them to turn around and blast away. 

I agree, it is a tough class to play. I'm not sure if its the toughest since I've been studying it even before I bought TF2, but its certainly tougher than most.

Regarding the strikes against enemy groups, it takes a while to clean up the aftermath of a pyro attack. Although it may not seem like much, it may be enough for your engineers to setup a defence. Whenever you strike an enemy force always try kill the medics before retreating, it makes the aftermath much harder to clean up.

Contrary to what is intended, the pyro is not the altimate CQC class, that distinction belongs to the heavy. The pyro is, perhaps, the best delay and distraction class. If you attack a soldier, the moment before he turns around run backwards and shotgun him. For the heavy, try to circle stafe him; and take out his medic if he has one.

I find that a pyro is good in groups. If you have a good group of 2/3 soilders or demomen or something, a pyro thrown in there can make the group much more effective.
Especially if the other team doesn't have a medic, but those days are over now, thanks to the patch.

I saw a guy calling spy was the easiest class to play and the soldier is the hardest... No he didn't say the opposite.

IMO it's spy and pyro. Everyone is looking out for spies today, and it's much harder to play spy today, if you compare it the day TF2 was released.

Hardest Class to play is obviously Civilian...

Spy IS the easiest class to play. Stop arguing with me!