I've been using the Logan 760-1 Simplex for years and have never had a complaint. A good supply of fresh blades goes a long way in getting things right the first time. If I was doing hundreds a week, yeah a top of the line pro model would be the only way to go, but 5 or 10 a month or even a week is just fine with the 760-1. I am sure the Logan 860 (60") would last a lifetime. Go for the extra 20 inches, I don't know how many times that has come in handy for me, scoring glass and plastics.
Later Larry