Don,
I have Photoshop CS3 Extended and must say that it works very well for HDR files. You probably know that I know virtually nothing about digital but I have always been very interested in my B&W work in capturing scenes of very high contrast. I recently purchased a small point and shoot digital camera (Canon G9) which allows me to capture RAW files at 12.1 mp. I used the camera extensively during a recent trip to Mexico, and ran into a lot of high contrast scenes that allowed me to make exposures for HDR images. The G9 is pretty neat because it will make three exposures at a time (on a tripod of course).
As I say, I know virtually nothing about digital, but using the automated HDR feature of CS3 Extended has worked out great in processing the RAW files from the Canon. I mean, it is like a piece of cake, and then once you get it processed you can do lots of editing in 32 bit. The only thing that I find really missing is curves.
In any event, I am attaching an HDR image from my trip to Mexico. The range from shadows to highlights on this shot was about 17 stops and it could never have been made in color with just one exposure. I posted the same file on the LF forum but thought you might be interested since you are talking about upgrading to CS3.
Sandy