Why fight it all. Bite the bullet get a Mac and PS. A Mac mini will do for a start.
I smell a troll ... :angel:
Darktable looks OK. Certainly it aspires to be much more than either shotwell or what ever used to ship with ubuntu. Looks pretty excellent reallly (as in having lots of potential). Right now it does seem slow (Core 2 Duo 2.53 - 4 gig of ram) but it's an early release. Not sure if a Lightroom inspired UI is necessarily the way to go - but it seems to have a pretty OK sort of UI despite my opinion and a lot more power than Shotwell has.
Of late I've been happy enough using shotwell and doing all of my editing in Gimp (all scans, mostly fixing dust and neg scratches with clone and doing the odd bit of grain reduction using the G'MIC plugin). Shotwell is OK for a simple holder that allows me to simply upload my photos to picasaweb online etc and it does an OK job of that for me (i.e simple and I don't have to think too much about getting pics online). Honestly I'm not sure if I'd be better off dumping shotwell and just using folders to store my photos and edit in gimp from their as needed. But shotwell does offer the option of reverting to original if I stuff up - which can be handy.
To install darktable on my Ubuntu I typed this in the terminal:
# sudo add-apt-repository ppa
😛mjdebruijn/darktable-release^C
# sudo apt-get update
# sudo apt-get install darktable
(it's about 7 mb's to download).
At any rate I find Linux great for my photographic needs. Gimp does pretty much anything I want. Hugin is excellent for pano's when I want them (never seem to use my VC15 Heliar any more these days). Philosophically the freedom implicit to Linux is also valuable in itself.
An open source effort (evil slr: Pentax S1a with $16 Elicar 128 @ 5.6). Forgive the blown highlights - that's my scanning and use of sunny 16 and not Gimp's fault:
Cheers,
Tyrone