Yup, I got thoughts...
Been an Evinrude guy since the beginning, then went to Yamis and now I am a confirmed Mercury guy. 35 of those years were with Stingray.
I just perused the Stingray web site and looked at some specs and prices. Look at the speeds and fuel efficiencies...the data is there. The 115 has more displacement. The upcharge is reasonable. I'd go with the 115 every day.
But I'll take it one step further. I personally feel that Mercury 4-strokes are the best outboards ever made. Lower maintenance requirements than the Yami and significantly more displacement, even though they are lighter weight.
I realize that would be an additional upcharge, but I believe the Merc 115 would be the best performer on that boat.