My new Bill Berg dulcimer!

Received it a few days ago and love the sound, shape, wood. Has 5 strings which I expect will lend a fuller sound. My question is: I have 3 different notes, a larger round McSpdden, a smaller squared off from Warren May, and a smaller round one that came with this dulcimer. When I use the McSpadden one it feels like I have less control/too bulky, hit the middle string. Both of the narrower ones are better for me, tho I do find less slipping around with the squared off one.

do others have similar experiences?