I am curious where you found the Beta 5, there is a new Beta 4.0.72 I noticed after reading your post.
Jon is very cautious about releases. Usually his Betas would be considered final in anyone else's product. I have rarely found a beta to have significant bugs. Sometimes will, but no more than what many companies pass off for final product. Still, I will usually play with any major update for several weeks before considering it for putting it into practice.
