I have two. A BErnina I purchased aobut twenty years ago and a new Brother. Both use the same PES format. The Bernina was actually made with a Brother patent so they are compatable. The first machine used little cards and I have several thousand dollars wrapped up in them as they usually ran about $100 a piece. I needed another machihe that would use the same format and the little cards. The new Brother uses both the little cards and a usb port that allows me to load in other designs. I had a Magic Box that allowed me to convert designs or load them on my old machine. Unfortuneatly I can not use it on my newer computer as it has not enough ports to load the Magic Box onto the computer.
What ever you purchase make sure it has the USB loading capacity. That will allow you to download lots of free stuff off of the internet and transfer them to your machine.
I prefer the stand alone embroidery machine like both of mine because I can be sewing on my sewing machine while the embroidery machine is doing it's thing.