I replaced the handlebars with the lower ones I found online.  The handlebars were an exact match other than the rise.  It's about 2" lower and feels better when I ride.  The fit seems to be closer to my regular bike.  More ride time will tell.
Marty57

New member here; looks like some great info. I have a RadRunner 3 plus; so far so good.  I am thinking of installing a lower rise handlebar for a slightly better lean for my back; bending forward some is more comfortable than sitting straight up. I found what looks like a perfect replacement to use with existing stem and all the accessories.  I'm wondering if anyone else has done this kind of a mod and how difficult was it?  Here's a link the the handlebars that seem to be an exact swap with about a 4" drop in the rise. 31.8mm to fit existing stem and 22.5 mm for all the accessories.  Thanks   
Marty57

https://www.performancebike.com/specialized-alloy-roll-handlebar-black-31.8mm-136mm-rise-680mm-s220800001/p1427985?v=1342563