i have played the Cursed founding chapters in 3rd and fourth edition..
I currently have a Legion of the Damned army and a Black Dragons force.
Legion of the Damned, which is defently my favorit chapter since I played second edition, is really dificult to play. Do to poorly worded special rules you have to explain them to your opponent before every game. Personally I am lucky enough to play in a store the no one objects to chapter approved armies much.
as far as a gamming army goes. You put yourself at a disadvantage as soon as you pay 20 points for a marine that losses "and they shall know no fear!" even though they are undead ghosts! they get scared hehe..
now the deployment is very dificult.. You would think being able to place anywhere on the board besides the enemies deployment zone would be easy.. its not.. its scary! you can really put you units close to each other (risk them crashing on top one another) but you dont want to be to close to the table edge.. cause in warhammer world.. the world is flat..and goin off the table opens a rift in the space time continuem and thats not good
with my legion of the damned I have always used lots of vehicle transports.. and I love the Abominations lead by chaplins.. I think its a very good idea to use rhinos.. they can come with hunter killers which helps a ton if you want them to deepstrike late in the game as a one shot wonder with their squad..
the legion of the damned is very hard to use because their marines can get to the combat fast but really dont have the options to be close combat monsters.. they dont shot very well because they are very expensive.. but with the rapid deployment and the ability to be in the opponents face turn 0 it pretty impresive.. I have used a land raider before full of Abominations and a chaplin Scatter into the enemies table quarter on turn 0(before the game deployment deepstrike rule) then get the first turn and the game started with me fighting incombat.. that happens pretty regularly actually.. this is important because for ever unit that scatters where it needs to be another scatters in the opposite direction.. Thats another reason the rhino helps so much.. redeployment after the scattter..
the army itself is solid and defently not over powered.. actually it is pretty underpowered because everything costs to much and they have limitations on everything...
However the black dragons are not something that takes a rocket science to figure out.. they are probibly the best cursed founding army out there.. Given the fourth edition rules with the chaplin..
Since you can easily ally 2 squads of Black Dragon marines as fast attack to any Codex marine army.. you basicly can have 2 amazing squads for chaplins to lead.. Assualt marines with Rending Talons and Reroll all misses on the charge is extremly powerful.. the price reduction for assualt marines basicly makes the black dragon assualt marine a steel.. hes 5 points more then a regular assualt marine but he comes with a pistol and 2 close combat rending talons (because his rending talons come off his elbows they dont lose there pistol hehe
I personnally recomend the legion of the damned as a fun army.. They are really awsome.. Also the best part about them is after you Convert and model them into Real legion of the damned marines They work both as Chaos Space Marines and Codex Space Marines..
Nothing like building an amazingly fluffy and fun army like legion of the damned then multi modeling them as 3 different armies!