I'm an amateur photographer who primarily uses Adobe Lightroom and Adobe Photoshop for post. Occasionally I'll use a standalone product for a specific effect, but I'd say 99% of my work is done in Lightroom/Photoshop. I've been frustrated with many company's switch to subscription based products (like Adobe Creative Cloud and Microsoft Office 365), and have been looking for alternatives.
Recently I have started using Darktable and Pixeluvo as Lightroom/Photoshop replacements and have found them to be very efficient and effective. I can do post on hundreds of images quickly with excellent results and rarely find myself missing features of their more expensive competition.
As for Pixeluvo, I really like the interface. It is modern, fast and clean. The dialog boxes for effects and such work extremely well and show very fast previews of what they will render. It can also handle RAW files, which is a huge plus. Basic photography workflow is typically opening, cropping/rotating, brightness/contrast, color saturation/temperature, resizing and sharpening for output. While a digital asset management program like Lightroom or Darktable is engineered specifically for working with large numbers of digital photographs and are very efficient at doing so, image editing programs like Photoshop and Pixeluvo are essential for individual image manipulation, especially where more technical work needs to be done such as with layers and compositioning.
I've only had one minor issue wth Pixeluvo on linux. I'm currently running Linux Mint 17 Cinnamon 64bit and for some reason when opening images within Pixeluvo, the highlighted file selected in the open dialog dissappears while selected. You can still open it, and if you mouse or keyboard to another file, it shows the previously selected file, but it is odd. I contacted the developer and they promptly investigated and replied saying they could reproduce the bug and are now looking into it. They said it was something specific to the Steam version as the standalone version did not show the same error. They even gave me a new license key for the standalone version, and they were correct, the file open bug is absent.
When traveling and editing photos, I like to take my Acer C720 Chromebook, which has a Haswell CPU and 4GB of memory. The SSD has been upgraded to 128GB drive, and the ChromeOS replaced with Linux Mint. For doing basic tasks, this very cheap computer with the SSD and running linux seems just as fast as my i5 an i7 systems. Obviously it has its limitations, but for quick and dirty content creation is certainly can do the job. Pixeluvo running on this system takes around 51MB of RAM and launches in around 2 seconds and uses 43.9MB of drive space. Darktable also launches in about 2 seconds and uses 110MB of RAM and uses less than 1MB of drive space. I do have Lightroom 5.2 and Photoshop CS6 installed on this system also with WINE and in comparison Photoshop launches in 8 seconds, uses 216MB of RAM and takes up 470MB of drive space, with Lightroom launching in 7 seconds, using 103MB of RAM and takes 920MB of drive space. The well programmed Pixeluvo and Darktable are small, fast and efficient at their tasks with their expensive competition the opposite.
I highly recommend this software.