With 4 DE BBs in a 1v1 you can simply sit there and out dps anyone with this setup. On reload with full cadence from kinc rewed batteries each BB does 88.2 dps. For comparison a retributions side macros with no modifiers do 15dps. I have yet to find a setup this can't facetank, maybe a crit tau build or craftworld? It can do easily do IN, Orks, Chaos and SM.
It's about all I ran into towards the end of the beta. The build simply works far too well. The DE shouldn't have universal stealth that immediately kicks in upon their turn and burn, dodge a massive amount of incoming fire, and be able to out damage any other faction in the game. By a far margin. Something needs to give. Their advantage should be in speed, a focus on knocking out shields to open up their assault options, and avoiding getting hit in the first place. For everything else they are given, outright dps should sit fairly low on their spectrum of advantages. Lower even then the other two eldar. To help differentiate them from the other two eldar factions, double down on their ability to inflict morale penalties. Winning by crippling fleets would be more in tune to their lore anyway.
They should probably decrease the rate of fire gained per second and/or the maximum possible total increase. I run 2 BB's (the torpedo ones) and 4 LC's (I don't remember which, but they're all identical), with Kin Crewed Batteries and the extended weapons range one, plus stasis bomb and troop killing bomb. It works pretty well, although it isn't invincible (not something I'm looking for anyway). As @Hellhound said, I believe DE should focus more on burst damage than in DPS. I do however like their stealth; all Eldar have it I think? Perhaps they should be a bit squishier to further punish mistakes, and put more focus on inflicting morale penalties as @Hellhound said.
I hope they can find a sweet balance spot for this and all other factions, because these OP-UP situations can wreck a community. I only recently started playing DE and it feels very bad to have so many players either inmediatly quitting when they see they'll play against DE, or some even throwing personal insults at me for using "an OP faction", or both. C'mon, I just want to play the factions I like, not ruin anyone's day. An unhealthy community is a short lived one.