Is DarkSend better, or it is exactly the same tech?
I've been following this development. Short answer: no one knows yet. The blockchain explorer for BCN ("Bytecoin") only just came online because its been hidden in the darknet for 2 years (it's basically 80% pre-mined during that time). They have the same functionality: CryptoNote's ring signatures mix transactions so that it only proves you were part of a group, not precisely who sent what to whom. DarkSend accomplishes the same thing using masternodes and pools, and it seems their degree of anonymity is similar (i.e. much more than BTC, but less than zero-knowledge proofs). I think which one is more successful depends on which ones develops faster and gains the network effect.
Remember that ring signatures were already talked about earlier in this thread, and iirc Evan mentioned possibly incorporating them in a future implementation of DarkSend.