For me the straw that broke the camels back was basting. I baste by hand and I LOATHE it. That said, I hated everything about basting by spray, glue, and pins. Basting just sucked the love out of quilting no matter how it was done.
I also had issues with quilting on my domestic. Sore shoulders and neck ... I would have to visit the chiropractor for several weeks after finishing each quilt. So I started looking at the sit down long arms and test drove them and LOVED them and I was >< this close to buying the Sweet 16 and then I remembered ... basting.
So I bought a long arm and moved it in to my husbands shop.
The down-side is that it's not at home so I really don't use it as often as I should. The up-side is that I don't have to baste. I really hate basting.