They have just released the Baikal N for Cryptonight and it is already obsolete with 20 kH/s. Bitmain announced the X3 with 220 kH/s hashing power. Needless to say what is going to happen with the difficulty of all Cryptonight currencies. Not to mention that almost all of the coin developers are thinking about switching to a non ASIC algorithm instead. It is not worth to buy any of the two miners.

There are algorithms that you shouldn't mess with. Ethash and Cryptonight are good examples for this.