There are three reasons
- Its RAW rendering is fast and decent. I would not suggest that it is a fantastic replacement for other RAW editor but it is is an ok conversion. The downside is it converts the RAW image into an 8 bit jpeg, and thus you will loose a some of the potential dynamic range,
- It now includes (from version 0.80) the ability to read and write metadata in .xmp sidecar files. Which means you can transfer rating and metadata into other photo mangers (that can read the adobe sidecar format). You have to go into settings under the browser/metadata tab and click on the options highlighted on the right. Again there is a small caveat in that XnView does not include a pick and reject flag (so useful in lighroom and other software) when first reviewing and culling newly loaded photos. Also the XMP compatibility does not extend to post processing options (just the metadata and ratings).I can not write to xmp in picasa so this is a big plus.
- It has a simple tools/import and sort feature that can load photo from a variety of dources (the can be camera, card readers, external drive, they just need to be connected to the computer and have a drive letter and/or folder directory. Whilst XnView MP does build a catalogue entry and thumbnail at this time it is way faster than lightroom for example. You can also add metadata and do some filtering by time (assuming the photo has EXIF data). It can also write data to a subdirectory yyyy_mm_dd according to the day it was photographed and this is how I like to organize my files
There is also the ability to read and write an extensive array (the web site claims 500 format) of graphic file formats. Ok there are only a few formats I regularly need but it is handy to be able to at least look at the strange files that turn up from time to time in graphic art. Thus this would make a great for managing the reference photos for a graphic artist who normally works in illustrator or Corel Draw/Painter.
I’m still only luke warm on it being able to replace picasa in my toolkit, but I have made a commitment to put this version on all my computers along side picasa and give it a fair work out.
One disappointment already is on the HP Spectre (2 in 1 windows 10 laptop) where it its decidedly awkward to use in tablet mode and where it can be very touch screen frustrating.