Pre-wound definitely. You get a better feed for your machine. You can probably find pre-wound somewhere cheaply online, I'd start with SewingMachine.com just because they're low price on so many items. The winder machine will wear out long before you get any savings out of it and it may or may not wind to a consistent tension and stay balanced left to right and right to left as it winds.

I most definitely use prewound bobbins..white and black. They hold much more thread than ones you wind yourself. I usually get 144 bobbins for around $22 delivered...sometimes less. I do have a stand alone bobbin winder as I do need my bobbin thread to match the top thread especially when I do FSL. The Brother or Baby Lock bobbin winders run around $160 or so, which is expensive. I did try the Simplicity one that JoAnn Fabrics sells and it is garbage. I would see if your dealer will give you a deal on one if you buy your machine from them... My dealer gave me 50% off of everything I purchased for my machine when I bought my Valiant.

I use pre wound bobbins too. They have more thread on them they are wound so neatly and I never get birds nests with them. I get them from AllStitch Give them a try and You will never go back to winding them yourself. Hope that helps you decide

I too use pre wound bobbins. My PR came with a box full, they are so convenient and last longer than ones you wind

I have both and I don't mind winding my own bobbins. I have a Simplicity or Singer I bought at Joann's. The first one is small and doesn't have the additional adapter posts for various machines, the second one does. I use a seperate thread stand, as it feeds better and I just sit and wind up bobbins. I love my prewounds, as everyone says they are tighter and have more thread on them but I have no problem winding my own. I embroider a lot. As far as being less expensive? I have a lot of bobbin thread that wasn't expensive.

I use prewound bobbins almost exclusively. A number of years ago, I did a cost analysis and discovered that prewound bobbins were cost effective.

Guess I’m going to have to try prewound after all these great comments.
So great to get info from other embroiderers! It helps me a lot when wondering about something!

It depends on the machine you have.
I tried them on my Husqvarna (the Designer one in the past, the Ruby now) and they don't fit them well. The stand-alone I tried did not accommodate those bobbins.
My Bernina 570QE has much larger bobbins, so that would never work. Thus I wind those on the Bernina.
My multi-needle and my old Brother 190D love the pre-wound.

My Ellisimo came with a bobbin centre pin and you put that in and then the bobbin. Found out what the centre pin was for when I had been given a couple of prewound bobbins to try but when I got home, I was looking at them wondering how they could work as they are not as high as the reg bobbins. Had to make a phone call - felt kind of silly when I found out what that little piece was for! Lol

Just another comment about pre-wounds... If you are getting a 10-needle machine, they do not have a built in bobbin winder so a stand-alone would be helpful... As another note, the bobbins for my 10-needle do not fit the built in bobbin winder on my Ellisimo...so a stand-alone was a necessity when I got my Valiant.