You probably wont need a rotary much once you get your paint looking descent. It is great for the heavy swirls and light scratches but other than that a PC will do just fine.
If you plan on doing more than just your own car on a regular basis, then go for it. I would be a little aprehensive about taking such a powerful tool to the paint of a fairly new lexus without having several hours of practice first.
Does the good outweigh the bad? I couldn't say. I see a lot of people getting incredible results with a PC, but a rotary is capable of so much more. It is also capable of doing more damage. It is not hard to cut through the clearcoat or burn the paint on your car.
I have a DeWalt DW849 rotary I purchased a short while ago and I like to think of it as riding a bicycle. Once you learn, you'll never forget, but at the same time, you are going to fall a few times while learning. Do you want to risk "falling" on the hood of your lexus? Probably not, which is why it is important to get that practice in.
Read as many posts as you can, and if you decide that a rotary is for you, then be sure to take your time learning the art of paint restoration. I wish you the best of luck and there are several members here who can help you if you get stumped.
NYD, Intel and others have given golden advice on this topic many times over and have possibly saved quite a few of us from being whipped like rented mules.
