No. Paragon Points are not saved with the D3 Armory. But, that is not really a problem. Especially once you hit Paragon 800. At that point you only need to check your Core Tab and your Details Sheet (Movement Speed).
For example, one of your builds may need all 50 Points in Movement Speed. Another build may only need a couple of Movement Speed Points. The difference being put into your Mainstat.
Or, if one build doesn’t have enough Vitality, you may want to add some Points there.
D3’s Armory is hands down better than D4’s Armory.
The first time I tried to use the D4 Armory it wouldn’t let me switch from the build I was currently using. Not a single item would switch out. After playing around with it for a few minutes I discovered I had to remove all my Gems and Runes before the Armory would switch my gear. After that, I could then insert the correct Gems and Runes for that build. When I wanted to switch back I had to repeat this process.
D3’s Armory doesn’t have this issue.