Bradford, I'm the same way. Pretty much every photo I process has had some treatment with either Denoise AI or Sharpen AI, or a combination of both. They can both work wonders, though I find that I have to play with the settings to get something that works, especially on images that have lots of clouds or water. So far, the main use I've had for Gigapixel AI is enlarging images for sky replacements - it does a good job with things that don't include a lot of detail.
This thread reminded me that I was going to buy Photo AI, so I logged into Topaz's website as I was typing this, and found out that it's already included in the bundle I have. That was a nice surprise.