Stuff I use that doesn't have equivalent/competitive products on Linux (I think):
* Downloader Pro (sorry)
* Neat Image
* Of course Photoshop is the gold standard and Gimp is not as good. Personally I use Photoshop, virtualized or native. I appreciate its wide variety of image sharpening options. But I do most of my work in Bibble Pro 5, which has a lot of things built in, like Noise Ninja, super quick and easy lens correction, hot pixel removal, etc.
* I hardly use the capabilities of Bridge (I don't have much need for it) so I can't say much about that, except to point out that Bibble can handle metadata, maintain an image database, etc.
* On the Qimage website the say it runs under Linux/Wine. I've only ever printed from my university so I can't comment.
* For panoramas, there are quite a few programs, but to be honest I've never done a panorama so others will have to comment.
* The Photomatix website says it works under Linux/Wine. There are also plenty of HDR programs under Linux. I hardly use any of these programs so I can't add much useful here.
As I mentioned earlier, Downloader Pro has lots of neat features. But I really do suspect Rapid Photo Downloader has some that it doesn't. For example, can Downloader Pro synchronize RAW+JPEG sequence numbers for images being downloaded from the same or different memory cards?