I have an extension table for 3 of my machines - my Husqvarna, Europro and Janome 6600. The Husqvarna is also my embroidery machine - so don't use it. My Janome came with a table which is much better, but I keep the extension table in the travel carrier. (I did use it when I was taking classes on how to use it.) My Europro is my travel machine and I like the table. Have thought about getting one for my FW. It is so hard to work on the small area. I would really love to get the FW table - but honestly do not have the space to use it. And it would be too much to take on vacation. (As it is my husband thinks I crazy for taking a sewing machine, he would go nuts if I wanted to take a table too.)
When I use the extension table it is while I am away from home and most settings are not ergonomically correct, so I don't sew for prolonged periods of time. That is when I make sure I get up and down a lot.
I would recommend getting one - it is so much better than just that small space.