I'm serious, yes, it's better. I'm not going to say it's as good as other apps. I mean, if you're keeping a to-do list, better to do that in Apple Reminders -- especially now that they've added that new shared list feature and assigning todos. But if you have to put up with Jira, then yes, I personally find the Jira app to be faster than the website. It reminds me why I like apps as much (or more) than websites.
I've also run Jira on a server before, and if you optimize the Java runtime's settings and over-provision, you can get a pretty fast Jira instance going. It's just most folks rarely touch the default configurations, which are terrible, or don't shell out for SSDs when running it. And the cloud version ... well, it seems a bit under-provisioned if you ask me. Jira doesn't appear to be written well enough to take full advantage of the cloud, yet.