I get along with DeNoise very well. I used to use Neat Image and could get what I wanted but thought the grass was greener elsewhere. When I switched to Mac I bought Noise Ninja without trying it first. Big mistake, while others manage to get good results with it and it always gets high ratings, I hated it. I could never figure out how to get what I wanted from it. I downloaded the trial version when my computer was in the shop and I was using PSE on my husband's computer. It was love within a few minutes, I get along very well with it.
Because of my experience with NN, I highly recommend you download the trial version of DeNoise and use it for the entire trial period. Kick the tires, read the manual and play with your own pictures with it. There's no guarantee you'll like it, just like I hated NN. But by the time the trial is up you'll know if you can't live without it or if you don't want to spend the time for it to process (it's not fast, even though the latest version is faster than the older one).