I've had one for over a year.
The best selling point for me was that they don't have to be replaced every so many years like other body protectors. So even though it seems like you're spending more money up front, you're really saving in the long-term.
My only issues with fit were in...
Before I got the iPhone I generally kept my old flip phone in my front jeans pocket or jacket if I was wearing breeches. The only time I didn't carry it was during the summer because the breeches I had didn't have any pockets so then it was left in my trunk in the barn. I do have a pommel bag...
I have put a crop in my boot but wouldn't have thought to put the phone there, will have to try it!
Good point about the glass & sweat as well as breakage. That hadn't crossed my mind!
As I am now a iPhone user, I was curious to see where everyone else carries their phone when riding? Anyone stick theirs inside a bp rather than side pocket?