Besides the thirty 'normal' missions, Battle Missions includes three 'special' missions - Linebreaker, Clash of Heroes, and Kill Team. I'm going to talk mostly about Kill Team, but will touch on the other two.
Linebreaker - take three Baneblades or other Apocalypse formation against a regular army of equivalent points. With some modification to the Victory Conditions could also be fun to use something like a horde of zombies or a Green Tide vs. a regular force.
Clash of Heroes - Kill the other guy's named character with yours. Nothing else can finish them off, and you track how much of the rest of the enemy your character kills. Some mods to the FOC, and not a good mission for 'support' HQs like Creed, you'll want a tough mofo for this one. From first glance it looks like there would be two basic strategies - one, try to pound the enemy HQ and finish him off with yours, or two, avoid hero combat and try to tarpit his hero while yours goes on an unstoppable rampage.
Not the same as the 4th ed version. 200pts, limited FOC, every model becomes its own unit (which makes a number of things much less useful, some things more powerful I would imagine). Cram as much terrain on the field as possible in a small (3x3 or 4x4) board and go to town in a semi-Necromunda type battle. No turn limit, but they claim it goes pretty quickly.
Out of the three, this is the one I look forward to the most. For even more fun I think you could incorporate some of the deployments and rules from other missions (and even later make a chart...) sometimes. Like using an Ambush type deployment or some kind of random zone deployment like in Night Fight. Or fight over a burning city like in Scorched Earth.
Something to note in the Victory Conditions - when an army hits its break point, it has to start taking Leadership tests with cumulative penalties - not Morale tests. So things like Stubborn or Fearless won't apply, and you won't have to hunt down every model of a Fearless force.
At such a low points level I think there has to be some more balancing factors. The FOC restrictions are one step, but I think there should be a few others.
Firstly, the more I think about it, the more in favor I am of just banning vehicles. Otherwise if you come expecting a shootout you could instead find yourself facing the War of the Worlds, as the other guy with the Valkyrie/Marbo army just flits around invincibly after taking out your couple of guys who might shoot it down. Sometimes it could work out, but I think at the very least you should inform your opponent of the vehicles you plan on taking so they can adjust their AT requirements.
Secondly, I think you should restrict models that can regain wounds or generate new models. After the third Chaos Spawn, etc. pops up you may start cursing those abilities. On the other hand the extra cost these units/abilities have may make it OK on the whole - but something to think about and pay attention to in your games.
OK, that wraps up my initial review! If you haven't yet, go back for parts one and two! Hopefully before long I'll be able to post up some battle reports using some of the missions, or even a Kill Team report!