When the new Chaos Codex came out, the Daemon options became laughably poor. A 5++ is pretty poor, and these guys can die quite easily to large amounts of firepower. But, like everything in the codex, it DOES, believe it or not, have a few nifty applications.

Firstly, let's look at the stat-line:

Lesser Daemons

With the same basic stat-line of a Marine, with higher Ld and more Attacks, these Daemons have the potential to look quite fierce on paper. Now, in reality, the 5++ doesn't make them last very long, but when used correctly I've found that they can get the job done. I take them in squads of 8, any more and your wasting points, and any less and you're not going to get much.

Some of my favorite Tactics with Lesser Daemons are as follows:

"Daemon Bomb": An old tactic from the old 'dex', I use a squad of Infiltrated Chosen (Or anything that can get close to the enemy, take your pick) and summon your Daemons behind Enemy lines. These Daemons can then tie up a unit of Devastators, Battlesuits, etc. This is useful against stand and shoot armies that don't like close quarters. Note however, that you will need about 2-3 units to be successful, as one unit can either be tied up and killed, becoming only a mere nuisance to rather than a significant threat. "Last Minute Objective Snatchers": As the daemons count as a troops choice, it's possible to DS them in or near an objective to contest/control it. I find this is particularly fantastic, as it gives you a trick up your sleeve which can help you win/tie the game.

Greater Daemons

Much, much better than Lesser Daemons, the Greater Daemon has a number of roles. A much better profile, though strangely enough the same initiative as their lesser brethren.

"Close Combat Monster": 5 Attacks with no armor save is nothing to sneeze at, and with it's relatively low point cost, it's almost a steal. As it is a monstrous creature, all the advantages that this confers applies to the Greater Daemon, and thus it can rip apart infantry and vehicles.

"Nasty Surprise": Greater Daemons are quite scarier than Lesser Daemons (Hence the Name) and if you take a bare minimum squad of CSM with an Aspiring Champion the not so scary squad of Chaos Marines becomes a lot more dangerous.

I hope this helps someone, thanks for reading!