I have the Pfaff 5.0. I have loved it for sewing, piecing, and I just now found the cool appliqué features (it has it's own stitch and these interesting "tapering" options when you come to a point like a star). The IDT as mentioned above is truly irreplaceable and unless other companies get on the band wagon, I'm not going to get any other brand of sewing machine without a dedicated and attached walking foot. My piecing looks amazing without the puckering you get without the IDT. The Pfaff features take a lot of "annoying" features of older machines and just zaps them away. Not having to lift the presser foot every time I need to turn a corner is awesome. Having an auto tie off is awesome.
However, there is one thing I couldn't make my machine do very well and that is FMQ. I have tried everything in the book and a few things not in the book. I have a separate ring stand, I've tried different feet, I have the slider, the heavy duty titanium needles. I have tested so many threads and even thread combos. The only one it worked "ok" with was Aurifil 50wt. I say "ok" because this machine is one where you cannot adjust the bobbin tension. All tension in on the top. I tried all of the feet, the 3 different settings for FMQ built in. The only one that sort of worked was the darning foot and I had to break that open with a set of pliers (it broke more than I would have liked but well...) Once I had all of the stuff lined out to do FMQ, it would still break thread - about every 60 -90 seconds. The stitches looked great, but the torsion on that needle when you go left will shred and break every time just about.
So, in all things sewing, piecing, and creating, this machine is amazing and precise. In all things FMQ....sheesh. Unless you are stitching in the ditch only... But the more I read about FMQ, the more I read that many - MANY - machines have similar issues. We could say that I just got a "bad" machine, that it needs servicing, that there something catching in the bobbin area....but ONLY when FMQ? Nothing else causes a problem? I keep coming to the conclusion that the reason people break down and buy a long arm (sit down or stand up) is to deal with these issues. The LA world uses a heavy duty motor and stronger needles. I broke down a got one a few weeks ago and it's amazing to sew off and on for hours without breaking thread one time. Now that I have that area squared away, I can really appreciate all the things my Pfaff can do.
Now....having said all of that....I've started looking at industrial machines - specifically lockstitch top and bottom walking foot machines. Why? Because of that motor! Watching Jordan Fabrics videos and seeing her ancient machine fire stitches so fast has me drooling. These industrial machines come on a serious and hefty table that.will.not.move. I have to say that when my Pfaff gets going, there is some vibration on the table - and I have it sitting on my dining room heavy wood table. I have the big BIG sew steady table too so I have kind of a large flat working area but when my machine gets moving (like when you are sewing jelly roll strips together) there is some shaking. I can't help but feel that the industrial machine that's nested into a heavy duty table would be kind of awesome. The problem is that you loose those awesome features of the Pfaff that make it so fun to sew on it feels like cheating.
Saying all of this....I see these on EBAY and for those prices, I would not hesitate to buy one. Seriously. What is the worst that could have happened to one? The only real moveable parts are totally replaceable cheaply. I saw one for under $600 the other day. I paid $2200 plus tax for mine a few years ago. That is so freaking painful to see.