Every bike I ever owned I mounted from the left side, then I got the Ultra. Seemed like I could never keep my leg high enough to avoid rubbing or tripping over the seat , backrest, etc. Somebody on this forum mentioned he would mount from the right side, grabbing the right handlebar with his left hand to swing his left leg over. First few times I tried it it felt unnatural but now it is the method I use every time. Very easy to get the leg high enough. Never drag my foot on the seat or backrest.
I get on on the left side, but off on the right. It's just easier for me to get off that way, especially if the Wife is riding with me. I had a guy who said that he taught an advance riding course tell me that getting off on the right side was "way too dangerous". He said I was going to hurt myself or someone else that way.
usually step thru from the high side - my left knee ain't what it used to be so don't trust putting weight on it. Although, I do mount from the low side on occassion.