First not to be a *#@*!##*, but the cookie cutter gear statement is funny as all your other gear besides the legacy set is, well.. cookie cutter :P
Anyways, your gear is pretty much BIS man, so besides busting out the visa there's not a lot of room for improvement there. But, your build could use some work IMO.
As it is now you only have 2 damage abilities (3, with rain of vengeance, every 30 secs..). You either turret RF while in gloom or you are vaulting around and shooting bola.. your edps is pretty crappy. None of your other skills do damage and 2 of your passives are defensive. Your damage is not amplified in any way outside of archery, you need synergy in your skills/passives. I will use my build as an example.
You are obviously experienced as a dh, so im sure you can come up with some things, and i do not own a l4n set. But some of these skills are applicable to you, especially the first 2.
1) Jagged spikes caltrops - these things do tons of damge, can crit( its just not yellow damage, i use these to proc the hell out of nightstalker, so i know they crit), you can stack them, and they don't break rapid fire channel. With l4n you can spam the hell out of these.
-I'd drop ROV for this
2) Cull the weak or steady aim.. easy dps gain right there. Steady aim snapshots so its fairly easy to keep up, but i go with cull the weak cuz i use caltrops and i find it more efficient to not have to worry if i snapshotted at range or not.
- I know you probably love your move speed with tactical advantage but if you want dps, its gotta go. You look like you need to keep perfectionist,
3) Chakram, shuriken cloud - It snapshots shadow power LS (OMG!) and works well with bombardment as you're stationary and mobs just blindly run in.
See the synergy in the build.. its like a damn blender. So where you spam RF, I have RF, multiple jagged spike caltrops, shuriken cloud and all that is magnified by cull the weak. That's EDPS.