I have been a big BD fan ever since I read the soul description when Rift was released (same as Stormcaller for my mage), however after extensively testing this soul I have come to some conclusions.
The problems with bladedancer are......
1. Multiple dance rotations. Every time a dance is used during that time your rotation change. 3 dances, 3 different rotations, this type of playstyle might be acceptable to oldschool "mage" players, but this isnt a mage soul, its a rogue soul. And since you can easily pull comparable dps with piss easy rotation in 61NB or NB/Sin, the complexity w/ not so impressive result makes this a very under-used soul.
2. Just like Sin, BD also has issue with disconnects as well whereas NB has easy mode disconnect utilities.
3. The offhand attacks (aka your main DPS output) does NOT work well with server latency at all. A lot of time I could sware I have used an "offhand-enabler" but due to lag my proceeding OH attack I am trying to use remain grayed out and cannot be used until like .2 to .3 second later making my GCD virtually 1.3s (which is a humongous dps loss).
BD is a fun soul with great concepts behind it. BUT just like Stormcaller imo, its a shame that virtually no one ever play it nowdays. Much effort is required for very little return compared to easy mode souls like Night Blade and Rift Blade.