yes you are quite restricted with it on, but it does what it was designed to, it takes my car lol, but i remove it for run of the mill everyday transporter work, although it does pick up a fair amount of expensive classic and hot rod work as well with it on, which is the market it was aimed at, normal transporters are 2 a penny, and getting work for them isnt easy, theres a lot of competition
legally the std 3.5 ton beavertails cant actually carry much anyway, most you see with anything much more than a small family car are operating overweight, especially the steel backed ones, the back on this is all aluminium to reduce the weght, and the floor construction is a newish design for strength, it also has air assisted suspension so it raises it and dosnt show the weight
generally you can tow more than you can carry with them as long as you leave the beavertail empty (train weight), but if you tow with any commercial vehicle for work purposes, you must have a tacho fitted and have the correct training to use it, another little european gem thats generally ignored lol, all ok till you get into a ministry pull over
a friend of mine has a steel backed one, and all it can legally carry is a ton, about a mk1 escort lol, and the bed isnt as strong as my aluminium one
there are a lot of additional operating costs and legislation to comply with by going bigger, and why its only the big outfits that generally go that way