I have similar problems, and I have seen that others have it to. The CPU is sky high and there are glitches in audio totally random. I play the same tracks with Traktor and Virtual DJ without any problems. I use the DDJ-RX with the software on a late 2010 2-core macbook pro.
Right now I have a totally unusable setup to play outside my own apartment!
Hopefully the next update will fix these severe problems.