ive done it both ways and there are some pros and cons !!!
without , i dont have anyone i have to share my sewing room with , trip over, clean up hairballs from, take material out of there mouth, yell at them to stop playing with that spool of thread, get off of that quilt, or wake them up from the comfy spot to go downstairs with me when im done sewing for the night,and to get out of the window !!! (there is a full lenght window in my sewing room upstairs and the dog can see everything going on in the neighborhood)
but i would miss all this if they were not here!!!