The most important feature, at least to me - picture resolution, is exactly the same in both versions. There are government restrictions the maximum resolution a satellite image available to the public can be.
The Pro version is more tailored to business use, but there are a couple of file transfer features for routes and GPS files that make things like that easier.
I had the pro version for many years, when it was $20/year! $399 is a lot, and I bet just marketing so they only have to offer and support one version in the future.