What's wrong with my bloody river?!? My river don't like you laughin'. I think you better appolgise to my river or it might flood on your ass!
As to things I learnt about the wave 2 models I had:
Fedayeen
I have had two battles involving Fedayeen, one at Mongoose Towers and one on my board. In the first, they proved useful. The AT-14 is a great anti-tank weapon but it was my suicidal charge at Ben2's Challenger tank to plant my IED's which was the highlight, especially as i managed to blow the damn thing up. The Sniper rifles also managed to take out a couple of his infantry. These are powerful weapons, especially as their range is good (36"). All round, the unit was very effective in this battle.
In my second battle they did not do much. My opponent was concerned about losing them too easily and they hung back. When they did come forward through a wood they paused inside the cover so they could not be seen. However, they had not counted on my Brit command unit working in tandem with a Challenger. I used a move action to enter the wood to get LOS of them (he had wasted a reaction earlier to move up in the wood). With my second action the tank blew holy hell of the unit, then with the COmmand extra action is moved back out of the wood, leaving the unit badly mauled and suppressed. So basically, in that battle they were pretty inefectual.
Brit Command Unit
This was very, very powerful. An extra action for a main tank, enabling it to move, fire and then move back out of sight, was a killer for the opposition. And it only cost 75 points. The fact that they don't have to be in LOS of the unit they give the extra action to means you can hide them far out of the way and do the business with your Challenger. This was by far the most effective unit on the battlefield.
Warrior
I like the warrior - its Target number means that small arms can't hurt it (as opposed to the MEA technical and the USMC Shadow). It has excellent anti-infantry weapons - 40mm Cannon 2xd10 and chain gun 3xd6. The 40mm cannon also has a chance of killing a tank if it is not in cover. All around, this was a good unit.
MEA Technicals
These present a tactical choice for the MEA player. They can carry 8 models, so unless you want to use multiple technicals per squad you need to limit MEA squad size to 8. You have to decide how you want to use them - transport or very modile MGs. Unlike Evil, I found they had a tendancy to die, as small arms fire can hurt them if not in cover and their armour roll is a 6+. They were useful in boosting up the MEA army cost but am not sure I wouldn't prefer another MEA squad and three extra MEA gunners to spread around then 3 technicals. I suppose it depends on how much fast movement is useful on the particular battlefield.
Shadow
Like the Technicals these were vulnerable to small arms fire if not in cover. There AT gun is excellent, and makes up for the fact that USMC infantry have no AT weapons. However, if they get into a fight with Armour then they go down quick. I think they would be very valuable in defensive positions, covering channels where enemy tanks could come down, but in open combat I think they die pretty easily.
Those were the only Wave 2 units I used in my battle.