A) TW Blue started as a clone of CN, actually.
B) it has huuuuuuge memory management issues (over 2 GB on a good day for me).
And C) try opening a huuuuuuge conversation. It will freeze literally everything but WX, because WX forces it's own thread down their throat.
I certainly see why people aren't that willing to fork over money, and it's actually quite understandable. But TW is not better in compareson imo.