Superman vs Lex was a major disappointment for me after wonderful first issue. They set up an interesting premise and do away with it very next issue in an underwhelming way. Another major problem for me was Lois talking about values and how dictators derail them. Thats all nice and fine, but she was explaining that to a robot who is created and programmed by Lex. I don't know, it just felt very preachy to me. Only one issue left so I'll stick it out and I hope that they manage to salvage this mini.
On the other hand I really, really enjoyed Batman/Superman, it even had a reference to Morrison's Batman and Robin #1!