That is honestly the one big advantage. I tried them and although they were good, etc having a different machine for each needle is better for me - the time it takes to switch back and forth from different tips I didn't find really made a differnce. I have machines that run similarly if not the same so if I need a mix of needles I just set up another machine.

In cases like traveling etc I can see the advantage but its not like carrying 4 machines instead of 2 is really that big of a hassle.

As soon as I started having issues with getting the carts I needed (they were constantly running out of stock) I gave up on it. Not worth it for me. But thats just me.