Thanks all.
Having read through the entirety of the LatD Redux thread before starting the Death Guard 0.3.x list, I hadn't seen any discussion of the Plague Tower in almost a year. As a result, I thought the 20cm move was a stable change and wasn't aware that it was still hotly contested. Hence this thread...
GORGONSAs far as the Gorgon comparison is concerned, I can understand but don't really agree - or think that it applies more to LatD than to Death Guard. What made Gorgons so stupidly good was their frankly
insane cheapness, they were a sixth the cost of a Plague Tower for half the robustness and being able to soak up hits made/makes a massive difference when the cargo has no armour. Anything in a Death Guard Plague Tower will usually want to be in base contact, and will be nearly as tough as the Tower. It's a local running joke that whenever I use a DG Retinue in Rhinos, they try to form a shieldwall in front of the Rhinos.
Then there's points costs - DKoK even with the roughly doubled points costs of the NetEA Gorgons is an army that can spam lots of cheap effective formations. The best equivalent you could manage with Death Guard is three stripped down DG Retinues and you can just about get the army up to nine activations by having the support formations be four-Pred companies or Plague Zombies. Spamming (non-scoring) Plague Zombies tends to mean losing activations really fast.
If you look at a DG Retinue with Chaos Spawn and Daemons you're
starting at 700pt for the formation with a 1pt Daemon Pool.
MAKEOVERAnyway, getting away from that, should we consider a bigger makeover? As Jimmy says, the current version is very unfocussed, neither fish nor fowl nor good red meat.
Looking for older inspiration, I no longer have a copy of the SM/TL-era Chaos box for the original rules, but the NetEpic Plague Tower seems to fit my memories fairly closely.
Notably, although it has a 75cm Rot Cannon with a ton of Barrage Points, the rest of the guns are 25cm and it gives a bonus when transported troops attacked big vehicles or buildings.
In terms of transport it could carry almost anything, but only had 11 slots, with a GUC taking up four.
Thinking aloud, here's a couple of more focussed ideas:
Assault Transport - we could keep the 20cm speed, tone down the guns and reduce the DC. For example make the Plague Mortar 60cm (maybe even 45cm) 3BP Disrupt IC and make the secondary guns 30-45cm. Maybe add a special rule like granting Ignore Cover to all units disembarking during an assault, or giving it Inspiring. Hmm, are there any War Engines with Infiltrate? That could be an interesting way to keep it at 15cm but make it useful as an assault transport, although a 30cm dash into combat would have it's own issues with suspension of disbelief.
Blitz Guard/Artillery - drop it back to 15cm or maybe even 10cm and up-gun it a bit. Possibly bump the Plague Mortar up to 75cm. We could also look at a 45cm Plague Mortar with Indirect Fire which would work much better with the Contagions, but big WE with Indirect Fire can be a pain to balance, as seen with the Ordinatus Medrengard.
EDIT - obviously an additional factor is that the Plague Tower is going to have different roles in the two lists. In Death Guard I've found it much more useful for assaults in it's own formation than as a transport, especially given the amount of good FF supporting fire in the rest of the list. Being able to wade in to almost any enemy formation and know that your attacking formation is likely to survive so your Blight Drones, Havocs etc. can support is powerful.