I like how big the screen is. No question, it looks great. The borders and bezzles are reasonably slim, too. But the phone is so big, and pretty heavy too. I actually have found myself gravitating back to my Stylo 3 because it's so much lighter and fits in my hand better.
It's definitely not a one-handed phone. Even when using both hands I find it more comfortable to cradle it in both hands, like a book. For typing this is a very ergonomic approach. And the keyboard is so wide that two thumb typing is a pleasure. In fact I'm using it now to write this and while it's nowhere near as fast as a desktop keyboard it's the first time I've found soft-key typing to be pleasant. No reason to dig out the stylus. Just tap away with your thumbs.
What's much less ergonomic is holding the phone with one hand and navigating apps/the web with the other. The weight, width, and depth just don't combine pleasently in my average-sized hands. Mostly, it's that the phone is so deep (thick) and the edges are close to square. Combined with the weight, the result cramps my hand. This is the largest phone I've used so I can't make good comparisons, but I know the Stylo 3 was just fine.
I'm also really disappointed about the stylus slot in the 5. Unless you have unusually large nails it's lodged too deep in the phone to remove. I find myself just not using it at all. I didn't pull the stylus out of the 3 all the time but I did use it (it was really nice for some games and for drawing). It's just not worth the trouble on the 5. Partly because the screen is so large. UI widgets and virtual keys are so large you just don't need it.
The speaker volume is good, and the sound is clear enough. I'm glad it's bottom firing, as opposed to on the back - you can set the phone down and not muffle it any.