I have both lap & floor.
I don't use the floor stand as much as I thought I would, as I find it harder to bend and twist my back to work the stitches. End up with a backache. I also find it harder to support the weight of the larger quilts with it.
I love my lap stand, it's portable, can use it in any room or even on the deck. I can adjust it easily, I actually have purchased 4 different size hoops to fit on it.
I currently am working on a king size bed quilt, I use a large oval hoop, sit on my bed at night, and support the weight of the quilt on the bed. It works perfectly.
By the way, I also use the lap stand to do my embroidery.
Hope this helped you and your decision.