The trade was good for the bucks. Payton is a better all-around player than Allen and will give the Bucks an interesting backcourt dynamic this year. This year being the key phrase, as Payton is a free-agent after the season and it is not clear whether he will stay with the team...
I agree that GP is a better player than RA is NOW, but you never know, he just started bubbling to become a phenonmenal player sometime soon!