I have two Fiskars rotary trimmers, both portable. Love them both. However the fold out arm popped off one of them (which is why I purchased the larger second one) but I put it back somehow. So they both are fabulous. It's just difficult on the larger one to read the measurements at 5 inches.
I saw the Martha Stewart trimmer and am thinking about how much I really need a 3rd trimmer (not), but I like the idea of the extension bar instead of an arm. Plus I saw it on HSN when they used it. But we shall see. I do love my Fiskar trimmers.