Supports HEVC, which is good for the long video plug-in, and applications that I expect to see in the future.
Newest Version is 16, but the 15 looks like it came out in 2018.
Solid reviews in PCWorld.
Note: it’s not clear if Vegas Pro 15 can edit 360 videos from the RICOH THETA with a 360 perspective (with navigation). I can’t find an obvious reference to 360 video editing. I suspect that it may only show the video in equirectangular.