I only have five to eight inch space for quilting on my long-arm/quilt frame. Would this be enough to buy a Q-bot.
I would love to have an 18 inch but they are costly so I will be staying with my Grand Quilter. I love the designs that
the Q-bot has but would it be worth it . So many quilts have eight to twelve inch squares and I don't know enough about them to make an intelligent decision.

I would think anything you buy would be severely limited by your lack of throat space. IMHO, the money would be better spent on increasing your throat space.

the qbot is not going to increase your throat space so you'll never be able to do a 12 inch block.

if you have design software you could take a 12 inch design and break it down into 4 inch sections and quilt out the design that way.

they do sell all over designs that the qbot can stitch out for a small throat machine.

Check the specs for Q-bot. Try their website. I saw on a flyer that it is compatible to some of the smaller machines. I am sure that the designs would be limited to the lesser throat space. I have been concidering it myself.

There are numerous smaller designs made for Qbot that are specifically for 9" throated machines. Look for qbots on sale...some can be found for around half what a new one costs.
You will be limited on space...but you can do some very pretty stuff with your machine & a Qbot

You can do a 12 inch block...it will take some setting up...but by doing a segment at a time, it's possible though, just as doing a 108 x 108 quilt on a 26 inch machine is....just takes some adjusting.