One fundamental problem with the codex is that for their points most things just aren't very killy- ie the potential damage your army can put out per turn is very low. I have the Dreads (and the vindicators too, to a degree) because for their points Chaos Dreads are one of the killiest things in the dex.
With careful positioning most issues can be overcome, there is certainly almost no need to have them killing your own troops.
Another problem is that each of the cult troops has a flaw- Noise Marines are overpriced and pay for a higher initiative they'll never use, Berserkers need an assault vehicle but don't get one, Thousand Sons have to pay for the ballast of an unwanted Sorcerer, and Plague Marines, while great backfield objective sitters, have no long range weapons. This is why the first iteration of this list had a squad with plasmaguns.
It would be possible to take normal CSM to make up for this but they are overpriced and have to be in 10s to get a long range weapon.
I agree that possession would be good on the Vindicators, but what is better, 3 Vindies or two with possession? I would argue that 3 is better, but how about a compromise and 2 vindicators with possession and a naked predator?
I also agree that Daemons would be good, but what is better, 5 plague marines in a rhino to sit on your objective, or 10 lesser daemons? Well I'm happy to try the daemon option, so lets give that a go.
Anyway if I do away with one squad and one Vindicator we get the following:
Daemon Prince, wings, MoN 150
Dreadnaught, ML, AC 110
Dreadnaught, ML, AC 110
Dreadnaught, ML, AC 110
Plague Marines x5
Meltagun x2
Icon
Rhino 175
Plague Marines x5
Meltagun x2
Icon
Rhino 175
Plague Marines x5
Meltagun x2
Icon
Rhino 175
Lesser Daemons x5 65
Lesser Daemons x5 65
Vindicator, Daemonic Possession 145
Vindcator, Daemonic Possession 145
Predator (with extra bolter cos there's 5 points left...) 75
Is this better? Thoughts? (I should say that this isn't meant to be a tournament list, but a 'hard' themed list that won't lose every time at the club/store!)