Well, in the end, the decision is yours, but you are absolutely correct about the wife. Now, if you have a specific reason why you want to keep the bed of the truck open, then ... there ya go. But if the bed of the truck is not a factor (for example you don't need it for storing stuff or transporting stuff when the 5er hitch is in there, then go for the 5er.)
In my case, my choice was a TT because I did not want to give up the shell (actually, that shell is a construction-contractor style cover with 2 full length shelves ... called tool boxes ... on each side, and the ladder rack is used to carry our canoe. So, no 5er). But if you don't mind loosing that space, go for the 5er and keep the wife happy.