everytime a new canary build comes out should i download it everytime or should i stick with my a little bit older version ??
you should keep your current build in case the newer build breaks or impact performance or features. citra currently is in constant update/changes, it may add features, fix graphical issues or impact performance but none of those is guaranteed on every single update.
Remember Canary is for work-in-progress/experimental code which means it can be unstable. Sometimes things will break unintentionally but are quickly addressed. This usually isn’t the case for Nightly where the code has been reviewed and tested.