How many lemmy instances have you signed up for?

Three, first on lemmy.ml, then programming.dev and also lemm.ee.

Lemmy.ml loads very slowly lately, probably due to the recent massive influx of Reddit refugees.

Programming.dev is fine, but from there I mostly see empty pages or less posts when visiting communities hosted on other instances.

Lemm.ee might be a good compromise: loads faster than lemmy.ml and a good generalist instance with a decent amount of users.