Four things
Whether the long runs are complete and in order; whether every episode carries its date; whether the dubs people grew up with are reachable; and whether the site works on a phone. On all four this is the site people came to AnimeXD for: the long-running shelf, the season tables, the audio menu on every service, and a phone-first layout.
For a rewatch
For a run you will rewatch, the services on the Watch now list are the better second place, and the free anime page says which cost nothing; the kids TV shows and the 2000s runs are often free.
