The tweak to disable mip maps essentially drops the texture quality. If it's really needed though it's a very good way to minimize stuttering, as is adding at least 1 frame of buffering.
If you disable mip maps I highly recommend forcing 16x AF in your GPU control panel though. Otherwise rock textures and such will look noticeably blurred.
If you really need to you can bump texture quality down to High vs Ultra. Some even on higher end cards are running it at Medium for the smoothest possible gameplay. Going from Ultra to High isn't very noticeable visually though.
Note as well that Far Cry 4 has been shown to produce an enormous amount of page faults when benched for it, so using a fairly large page file can help.
Some put their page file on an SSD, but that can cause excessive wear and tear on it. What I did was create a 15GB partition on the edge of the platter of my new WD Black 1TB HDD.
My page file partition benches at about 180Mb/s, and now it's on a drive that can easily handle lots of writes and erases. A hybrid HDD/SSD would probably work even better.
Note if you already have a fair amount of files on your HDD, you can still use a partitioning tool to place the partition on the edge of the platter. I used Partition Wizard, it's a great tool.
Note that these tips are more for stability than FPS increase. The game can handle 40 or even dips to 35 FPS, as long as the stutter is dealt with.