Actually the play results have changed considerably. They still need some tweaking, sure, but they are quite a bit different than 2.0 and I've posted the details many times. But the proof is in the pudding and if you don't think you see changes, I'm not going to tell you you're wrong.
As far as Sim AI teams always losing, that might be a philosophy on whatever other site you play, but that's not the game we've built. It's not about the house winning, but rather about you playing a competitive game. Ideally, all the teams would be filled with human coaches, but we know that's not going to happen, so to keep the game competitive, we treat Sim AI teams and their coaching similar to a basic level of human coaching. Some people want to equate a Sim AI team to a coachless team, but there's a BIG difference between a team with a human coach that isn't playing and a Sim AI team. Granted, I think many things can be improved for Sim AI teams, especially around recruiting, but I don't think they should ever be automatic wins. We also have to keep Sim AI teams relatively competitive due to the nature of how users take over teams. We'd have to change a lot about the game to remove the way Sim AI teams are treated.
As for Sim AI teams in the beta, they are unnaturally more talented at this point than usual due to the fact that every team had players generated and placed on the teams so that you could pick a team. Players are generated before users take teams so there's no concept of Sim AI team versus human team at that point. There are many Sim AI teams (teams that no users had picked) that have great players on them. While game plans are hopefully more relevant now, a Sim AI team using the basic balanced game plan is going to do pretty well with great players.