I'm loving it so far- it's probably the best privacy focused g suite alternative I've found. It's easy enough to use that even the non-technical among us can use it
I actually haven't found it that slow, but I've also kept my expectations low. I'm willing to allow some slowness in the initial document load time if it means I get some privacy.
I haven't had it take that long, but I have noticed that loading time varies between mobile and desktop. Not surprisingly, the more powerful device loads the document faster
Edit: You're right- it takes like 10 seconds on my phone. I decided to time it