Animwatch has a lot of bugs + it doesn't have download option + no quality option (only 720p and 1080p) + no MAL or SIMKL import and export(MAL integration) so I think AniMixPlay is better.
Of u want to use sites like 9anime , kickassanime, 4anime, gogoanime with a better UI, with myanimelist sync, with download option (even with those sites which doesn't have the option to download) use AniMixPlay it's the best site for me and it's really underrated.