Not sure which other machines may be the same as the LSZ1. I can however attest to Sailrite's customer service and the machine's quality. I have spent several hours on the phone with them concerning the care and feeding of the machine.
Most recently they helped me set up the machine to facilitate the use of Gore Tenara thread. Not an easy task.
The machine may be more expensive, but the service is 2nd to none. Worth the the extra $ to me.