Hi, you have this posted in the Developers space...are you wanting to know differences for development specifically, or just the software? Quick comments about development (and there are others) is the version of Python used, and Python addins are not available (although custom Python tools can be modified and many can be made to work). If the deveopment is the IINFO you are looking for, I/we can offer more specifics. (If not, we may want to move the post)
if looking for the software in general, actual pros/cons is a bit subjective, and there are many threads posted on geonet already. The functionality between Pro and ArcMap/Catlog is not 100% in place yet, but they expect most to be migrated by the end of the year, I believe. Some things may never be ported over, and in particular, one of the things many of us data managers have an issue with is the lack of simple ArcCatlog functions (without starting a Pro project). If this is a concern for you too, please vote up the idea for a standalone (I'll come back and post the link).
These sites have info that might help, and the road map will be a good blog to follow and it is updated with new info with each release.
http://www.esri.com/~/media/files/pdfs/library/whitepapers/pdfs/arcmap-functionality-matrix.pdf Haven't been able to find the 10.5.x version, but this is for 10.4.x
The rumblings are that ArcMap will go the way of the dinosaur, but not as a conscious effort on the part of Esri, but as Pro will become more capable and demand will shift from ArcMap.
There's a roadmap of near and long-term coming features that was presented at UC - I'll see if I can dig-up the YouTube link when it becomes available.
Chris I think it will be quite a few years before Desktop becomes unusable, even if the support and software it retire in another 6 or so years (maybe). https://community.esri.com/thread/198430-uc-whiplash Is a recent discussion on this topic.
Rebecca, the functionality matrix in your last link is the last kick at the can.
There won't be one I am sure comparing 10.5.1 with Pro 2.0 would be my guess since too much changed and I suspect the changes would be too great over time.
The 'What's New section of the Py Links is probably about as close as you are going to get if one is looking for the presence of a particular function
True. Still not sure if the OP was looking for development or just functionality in general, not that it matters. But still say pros/cons is subjective. I still believe in using the tool that works for you, but with that said, Pro is not going to work for everyone yet. Cause in point, I had to wait until Desktop 10.0 before I could move my databases to ArcSDE instead of coverages because the topology had a major bug, so editing was being done in Workstation at that time, even though maps and other tasks were done in Desktop. So, there will be overlap for many of us...and even after the lifecycle of Desktop fades, it may still work. But yes, Pro does seem to be the wave of the future, and you Py links blogs are great for keeping up on all the development trends.