Originally Posted by Lori S

If a dealer told me that a machine was finiky and had preference for a particular thread ... I would not buy the machine. I have two machines , a Singer 306W and a Viking... Niether would not be in my house if they were fussy. I use everything from cheap serger thread , invisable thread, metalic , you name it I run it threw my machines. None have suffered .
I do have quite an inventory of various needles , as mentioned most issues can be resolved with the right needle or thread path. Keeping a good cleaning schedule ( for lint issues) is important if the thread is linty.