Both offer premium memberships, and can often be really restricting when viewing/downloading data.

The main feature I added because of WhaleWisdom was the data download. For any filer you can download all data in CSV or JSON, as on WhaleWisdom that's unavailable. I also plan to add a bunch of features those sites have eventually.

Yeah, I'll throw my SEC Filings site https://Last10K.com into the mix too that has a free feature on how a manager's portfolio changed by tagging which stocks are new / sold / increased / decreased from the previous to current quarter. Here's an example from the OP's "Popular" and "Top" filers:

Tiger Global: https://last10k.com/sec-filings/1167483

Ruane, Cunniff Goldfarb: https://last10k.com/sec-filings/1720792