Their new version (2018.5) for Windows finally fixed an issue I
complained to them about at least a year ago. When in develop mode,
and arrow keying through the filmstrip, it changes to the next photo
pretty much instantly now. The delay of at least a few seconds (with
raw files) used to drive me nuts. I'm assuming that they also fixed a
related crash issue, but I haven't checked that yet.

2018.5 is also a free upgrade if you own 2018. Some of their
promotional emails seemed to imply that you had to pay for an upgrade.
They also have a promotional price for their latest version of NIK. I
believe it's $49.