As a 9.7" iPad Pro owner, I can say the 4 speakers really sound nice and add a lot of volume when watching YouTube clips or Netflix on my desk. So I think they would help the iPhone as well. However, I'm not sure how I feel about the lack of a headphone jack. I do use mine a lot when not in my car. (And I'm one of those that use the included white ear pods most of the time and think they sound pretty good for what they are--they work fine for phone calls and pod casts. I also have a nice pair of Bose in-ear headphones but they are starting to come apart near the wire-to-headphone junctions so I am afraid to use them in any way that might pull on them too hard and kill them completely.) Though maybe Apple knows best and lightning head phones or a decent pair Bluetooth ones will be the way for me to go in the future.
I also have a MacBook with the single USB-C. That hasn't proved to be that much of an inconvenience to get used to and it seemed like just about everybody spouted no end of doom and gloom for Apple on these forums and how nobody would buy it and they'd have to go back to Windows laptops. It's fine and I think the MacBooks are selling pretty well actually. So losing the headphone jack is probably not that big a deal either.
I am a little worried about the idea of a lightning adapter or lightning headphones plugged in when the iPhone is in a pocket, though. I feel that the skinny "long" side of the adapter will be potentially easy to snap off.
Oh, and if that is an actual purple color and not just some weird photo lighting effect on a Space Gray case, I kind of like it. Not sure I'd consider owning it unless the front was black like the SG, but it's way better, to me, than the Rose Gold (pink!) one.