Well, the other one would be Pro because it would require we install it. This one doesn't have a scoring function as it only really would work on certain servers. Shared servers may have issues with this. It comes down to just making sure people have options. At this time, since we haven't released Pro (and may never, as we never did with XenForo 1) you can assume this is the only trending product we may have for the foreseeable future. A pause has been placed on Pro, and will evaluate whether it is wise for us to put a scoring function on people's sites where it may eat resources if calibrated incorrectly.
All in all, I foresee if we do a Pro the part that makes it pro is the setup and some advanced tools. But 90% feature parity otherwise.
What do you mean "scoring function"? You mean some sort of trending calculation algorithm that weights likes, posts, recency, etc? Without that (if that's what's missing from this version), how does this version even work out what's trending?