When Sling TV started teasing a new version of its app last week, it looked like a major step up for the live streaming service.

Sling’s interface has always felt a bit crusty, especially compared to slicker live TV services like YouTube TV and FuboTV. The update, which is rolling out now on Amazon Fire TV devices and and heading to other platforms throughout the year, gives Sling a more modern look, simpler menus, and a some new navigation features.

Now that I’ve had a chance to try the new Sling app myself, I can confirm that it’s a big improvement. There’s just one problem: The pre-release version I’ve been testing can be excruciatingly slow, especially while using the channel guide. Hopefully that’ll change before Sling rolls it out to its regular subscribers.