Hey Archoncryx. Sorry you are bummed out about the Dark Eldar at the moment. You hit on a couple of key things that I do agree with... you do have to choose wisely when building a Dark Eldar army. You can't just dart throw an army together like you can with the Eldar and compete against upper tier armies.
That beings said I think the DE are still a good solid army. Like you said, Venoms, Reavers and Razorwings are all very good to excellent units. But their are a number of other units out there are VERY good as well. Grotesques, Talos, Kronos are very good, the Corpsethief is excellent as is the Grotesqurie from the Haemonculus Covens. Not to mention the Realspace Raiders Detachment which allows you to cram as many Reavers as you can into your army.
I would hardly describe this as rock bottom though. I think armies like Orks and Chaos Space Marines (before the Traitor Legions) had been staring into a far darker abyss than the Dark Eldar.
The 7th ed book is more challenging and less characterful than the 5th ed book while their are quality niche units that are challenging but playable units to add to your force besides the excellent choices I mentioned above. Incubi, Beastpacks, Sslyth, Ravagers True Born and even small objective holding units of Mandrakes all make for a good spread of quality units. Yes there are trash units like Hellions, Wyches, Wracks, Bloodbrides and some of the Court of the Archon choices suck... and while its a shame it doesn't make for a lost cause.
So we've got the following excellent choices: Venoms, Warriors, Grotesques, Reavers, Razorwings, Talos, Kronos, Grotesquerie, Corspe-Thief and Realspace Raiders.
Mid-Tier Quality Units: Ravagers, True Born, Beastpacks, Incubi and on the edge... Mandrakes....
I'd say all in all thats a good spread of units that offer a great variety of play. If you are looking for tangible "proof" of their quality I'd highly suggest checking out Lawrence from Tabletop Tactics. He's an amazing painter and ultra competitive tournament player. He's won the No Retreat ITC tournament in Gibraltar three times in a row with his Dark Eldar, taking three different lists each time... even taking a tooled up Archon for fun. He's going to LVO this year and I will be rooting for him.Vox Cast Transmission 13: No Retreat III Tournament Report - YouTube
I feel your pain on Wyches, Bloodbrides, Hellions and difficulty in running some of those mid-tier options but all hope is not lost! Check out Lawrence from Tabletop Tactics and some his fantastic Dark Eldar battle reports and you will see that while challenging a bit spammy to play Dark Eldar can still eviscerate opponents in the hands of a skilled general.
Take heart and keep on raiding good sir! Let me know what you think