Without a doubt I get more of my best shots with my 45-85 zoom, which is wide angle on my 645 camera. It's a nice sharp lens. At least 90% of the time I shoot at 45mm but nice to have a normal end to work with when you want it.
I almost never carry spare lenses so that is a factor as well. Whatever lens I have on the camera is what I am shooting with so in that case having a zoom is a bonus.
I hear you on the "one lens-one camera" preference. Cool photos; is that a bit of barrel distortion I see?