Could anyone give me a good comparison review between Fallen and Valkyrie set?
I'm really interested in both theese armor, but i have no idea wich one to choose.
the reviews i've come across arent to fulfilling, and ive been looking around for a hour now and still havent found any proper threads that propertly compares theese armor sets without turning unserius and personal.
I dont know wich to choose really.
basicly, all i've learned is: Do not use faust with fallen. thats basicly it. and angelic has bad fire penalty.

Plan to run the Firestorm Citadel ever in your life?
Fallen set. Unless you like being on fire; I hear it gets cold in hell.

These aren't really Firestorm Citadel sets, they are good for other gates, but I'd say they are secondary sets for after already having a great 5* set that is flexible. (If you choose the Fallen set there are fiend enemies in FSC, and you've already heard about fire resist penalties for Valk.)
Low attack speed isn't really noticeable, medium a bit noticeable but in my opinion not worth doing 4 levels lower damage to fiends. Medium IAS may be useful if you have equal amounts of guns and swords, but even then I'd probably choose Vog because of how little speed effects guns when you count in reloading. Negative fire resist is killer on most levels, again why I insist you don't main with these sets unless you are going to avoid all fire themed stratums, or you will muscle through them. The only time you may need curse resist is for a Faust or against Phantoms, which isn't really a bonus.
The reason why the threads comparing them don't really happen much is because of how opinion based it will be to decide between them. So all in all, it's your opinion on what you feel you want in armor.

If you choose the Fallen set there are fiend enemies in FSC
Maybe 8-9 Trojan Knights and the damage is negligible. It's hardly noticeable or relevant at all, but I do understand your point.
I'm in the same boat as you are. I have the seraphic chestpiece and I've got a wyvern scale helm. All together, my fire resist sits at zero.
Now, to me, it seems to come down to two things:
1. How much do you hate fire?
2. How much do you hate fiends?
The change in damage to fiends isn't negligible, it's going to be a %25 change in damage done to them. Personally, I hate the little office beasts, as adorable as they are. I believe that curse resist is pretty useless at the moment, since nobody curses you so all that you have to think about is fire. I think I can deal with fiends, particularly if I get a faster attack speed and fire resist.
Also, armor of the fallen, it looks really cool.