Working on the 32-bit image in Lightroom will give you far more flexibility and enable you to do a lot more. Julianne Kost produced a quick tip for Lightroom 4.1 that explains the benefits of doing your HDR images this way. You might want to take a look. Of course everything she shows still holds true in Lightroom 5.
Thanks, Jim; yes, I saw Ms Kost's video on this and that's actually what prompted my question, since she didn't come right out and say that keeping the image in 32-bit and sending it back to Lightroom would produce a better result. I was a bit suspicious since, in general, Photoshop is a much more robust app than Lightroom.
It seems to me that she implied that the 32-bit image would contain much more data, giving you a lot more to work with in Lightroom. The beauty of working on the image in Lightroom is a you have all of the raw editing functions available to you. I don't do a lot with HDR. I have tried a couple, but haven't really seen a lot of advantage. If I were doing HDR, I would do the 32-bit image and then do as much of the finishing as I could in Lightroom because I like the tools in Lightroom. You'll have to decide for yourself. Try it both ways and see if you can see any difference.