Doug,
I've been running one for several years now, and regularly field calls from other prospective buyers, since I left a review on the SS sight a few years ago. They called me a month ago to say thanks, as apparently, I've helped them sell a few!
I suggest you read that review, if you haven't had the chance yet. I stand by what I stated there to this day. Solid machine, very good results. Only other sanders I've run in the past would be a 13" Timesaver (cool old jalopy!), the perennial jet 16/32 drum (naturally, worst of the bunch), a relatively worn SCM 36" Sandya, and for the last 6-8 years, this 4375 by Safety Speed. Definitely at the top of performance results - right on par or better than the SCM, but again, it was a bit tired (dry/hardening conveyor rubber, abused contact roller, etc. )
Go 20HP 3ph if you can.
No regrets - will probably easily last the next 10-15 years of my career as a one-person shop. Very glad I sought a 43 over 36 - really quite the advantage if, like me, you do a few table tops and large door assemblies. Heck, even face-frames can exceed 36" capacity in a true custom shop, so at very least, I say, stick with that width.
Jeff