For a small team, I can say Linear beats the hell out of JIRA. I sure don't miss the 30+ second page loads, slow pagelads, slow saves, slow edit button, confusing comments section, and accidental random ticket body erasure when working with a heavily loaded JIRA instance.
What is causing your JIRA projects to take that long? Too many custom fields? Large numbers of issues? Too many plugins? Really curious because most of our issues are sub-second.