I personally would not want to fly anything other than Freight.. it's very relaxed and fun flying..
but some say that a big draw back is that you have a life style as a BAT... awake all night and sleep all day... if you can live with that it can be great way to operate.... not many of the Pax airline perks.. i.e. cheap flights,, and positioning for great distances in the back of a freighter can sometimes be a drag.. but with a good crew it can also be a blast...
anyway.. if you ask me,,, and you did... Flying Freight "rocks !!".....
But, having said that.... i've never done anything else.