Now that all of the battlegroups are plastic, I think it's time to look at each and I will rate them based on two criteria: 1) Value - compared to the cost of purchasing the models separately, and 2) Longevity - how useful will the models be for building lists and expanding on the faction in the future. I like to give weighted values to these, so while I might seem a bit harsh on particular scales, I do rate them relative to each other. For the record, I think that all of the battlegroups are worth buying because they are at least 25% cheaper than buying the models separately and they all give a great feel for what the game is like.
Contents:
Coleman Striker
Ironclad
Charger
Lancer
Value: (4/5) $80.96 Retail vs. $49.99 or 38.25% savings.
Longevity: (2/5) pStryker unfortunately is not a terribly popular warcaster, in spite of his toolbox of useful spells. While the rest of the models in the battlegroup are useful in certain situations, they unfortunately will rarely find themselves all in the same list. While they are great for branching out and trying other warcasters, they aren't going to save you from spending lots of money later to fill out other lists.
Contents:
Kommander Sorscha
Juggernaut
Destroyer
Value: (3/5) $77.97 Retail vs. $49.99 or 35.89% savings.
Longevity: (3/5) Sorscha is quite a common warcaster in Khador because of her battlegroup box and the warjacks you get in this particular box will generally find their way into many lists early on. Khador tends to take a 'combined arms' approach anyway so you'll want to pick up some Winter Guard early, but the warjacks included in the box are quite useful for being cheap (Juggernaut) and versatile (Destroyer).
Contents:
High Exemplar Kreoss
Crusader
Revenger
Repenter
Value: (5/5) $84.96 Retail vs. $49.99 or 41.16% savings.
Longevity*: (2/5) Kreoss can be quite the useful starting warcaster and many Menoth players won't need to look far past Kreoss for effectiveness between a solid feat and access to Purification. Unfortunately, many of the other models in the battlegroup box are rarely seen unless they are spammed (Crusader) or the player has a very specific purpose in mind.
*If you consider the Menoth half of the Two Player Battle Box equivalent (replacing a Revenger for a Vanquisher), then the Longevity score would be 4/5 instead. The Vanquisher is an awesome warjack and is useful for quite a large number of Menite warcasters.
Contents:
Warwitch Deneghra
Slayer
Deathripper
Deathripper
Defiler
Value: (2/5) $74.92 Retail vs. $49.99 or 33.28% savings.
Longevity: (4/5) Deneghra is probably the most potent of the battlegroup warcasters and will keep you entertained and competitive for some time after you pick her up. Even if you don't wish to use her, the warjacks she comes with are great arc nodes that can find their way into most any list and the Slayer is an all-around great warjack that is also cheap.
Trollbloods BattlegroupContents:
Madrak Ironhide
Troll Axer
Troll Impaler
Troll Impaler
Value: (5/5) $83.96 Retail (uses prices of current metal versions of models) vs. $49.99 or 40.46% savings.
Longevity: (4/5) The Trollbloods battlegroup is definitely one of the ones which is most useful for a burgeoning Trollbloods player. While Madrak himself might not always see play, the animus of the Impaler is a huge boon for most of the ranged models in the faction. The Axer - although expensive for a light - similarly sports an awesome animus which extends the melee threat ranges of Troll models and also has one of the few thresher attacks with reach. While it might not be the best battlegroup when matched against the others, the models will certainly be very useful with other warlocks in the faction.
Circle BattlegroupContents:
Kaya the Wildborne
Feral Warpwolf
Argus
Argus
Value: (2/5) $73.87 Retail (using the price of the current metal version of the Argus) vs. $49.99 or 32.33% savings.
Longevity: (2/5) As much as I personally like pKaya, she's often considered one of the weaker of the Circle warlocks - especially compared to her epic form. Similarly, as great as the Feral Warpwolf is at wrecking enemy heavies, he is oft-maligned in lieu of the Stalker. Finally, the Argus is largely considered to be the worst Circle warbeast out there - despite my arguments to the contrary. As much as I would personally like to give this a better score, I think the Circle battlegroup models will rarely see play outside of games with just these models.
Contents:
Master Tormentor Morghoul
Titan Gladiator
Cyclops Savage
Cyclops Savage
Value: (5/5) $83.96 Retail vs. $49.99 or 40.46% savings.
Longevity: (3/5) Master Morghoul is largely considered to be one of the top warlocks amongst certain Skorne players (and largely considered better than his epic version). Additionally, the Titan Gladiator is one of the best warbeasts in the game for his point cost and can find his way into literally every list for Skorne warlocks. Unfortunately, the two Savages are not going to be nearly as versatile and while you might occasionally see one of them tossed into a list, using two of them is unheard of unless you have a specific idea in mind (like running only Cyclops models or something like that).
Contents:
Lylith, Herald of Everblight
Carnivean
Shredder
Shredder
Shredder
Shredder
Value: (1/5) $66.96 Retail (using the price of the current metal Shredders) vs. $49.99 or 25.34% savings.
Longevity: (5/5) pLylith is a fairly effective warlock who's also pretty fun and easy to play. On top of that, the Shredder is such a ubiquitous warbeast that even if you don't put them directly in your list, they're worth having just to for them to pop out of the Spawning Vessel. Lastly, the Carnivean is quite the solid and powerful warbeast that is very versatile - which high powered attacks and an amazing animus. You'll find these models used in a wide variety of lists and you won't regret having them around.