Hi guzzibob, I am evaluating LR5.2 on a Mac Pro running Mountain Lion 10.8.5. I completed an entire workflow routine for a pregnancy shoot and there were no issues.
But I am with Cletus on this point: this only says so much about using version 5.2 in my situation, with my workflow. Yours may be different.
I did find some nice added features that make version 5.x a worthwhile upgrade. So I am determined to buy when my trial period is over. However, you may not find any of the new features beneficial to your own workflow. If that were the case for me, I would not upgrade.
I suggest you have a look at the added features and what other photographers say about them in blogs and forums such as this. If you like them, just get the trial and see for yourself!