While I would generally agree with most things said on this thread, a 545 is a walking for or compound feed machine, I have used Pfaff 145, 545 and all three current models of the 1245. They are all compund feed machines. The biggest difference is the body casting and the 145 has a small bobbin and the 545 and 1245's all have large bobbins.
If you want any of these machines, be aware that there is and H3 and an H4 version. The H4 has a higher lift and is much better for sewing thicker materials, especially with welt.
I live in Tampa and if it is OK with this site, you can call me at
813-837-9325. I'll give you as much info as you want on the machines.