Escort is the boss I wanted in w3, a pug-friendly boss that is accessible to all levels of raiders and gives them something to do besides wipe on Vale Guardian, boss 1 of wing 1, all day long. Boss 1 of wing 2, Slothasor, is widely regarded as the least puggable boss in the entire raid. Unfortunately, wing 3 failed on my other expectation, that its final boss--the final boss of the entire raid encounter--would be more difficult than the other bosses. Instead, it is easier than the second boss of Stronghold of the Faithful, and I'd guess the majority of wipes aren't due to lack of healing, dps, tanking, or fight mechanics, but the sheer stupidity of falling off of (or failing to be on) ley lines, a flying -style mechanic in the open world that's also necessary in wing 3 of the raid.
Anyway, Escort has two challenges: the tower group needs to perform through some burst healing and dps challenges, and the ground group needs to use their cc, has enough burst dps, and perform the fight macro in the correct order. It took us, as a guild, about an hour and a half to down the first time, about an hour to kill the second week, and this was a one-shot (hence the horribad spec).
Another nice thing about the boss is that it doesn't necessitate comps. Sure, I wish the final boss fight was harder, but the fact that we could include some new people without class flexibility was very nice. Our tower group traditionally consists of a chronomancer in stealth/blink spec (hence why the revenant isn't in his subgroup for boonshare), a dragonhunter, and an auramancer tempest. We don't blow up the tower mobs as quickly as some groups, but we are also completely self-sufficient.
The ground group brings a lot of immobilize, cripple, and a druid healer to control Glenna and keep the group alive. Dragonhunters have some very nice cc they can use on the wargs, and syvlari can use grasping vines on something other than Gorseval spirits. We had to reset our composition once we swapped to other bosses, but I'm very happy that people have learned the fight and we can rotate new people in and out as a guild.