I felt exactly the same!!!
I liked
Part II until I discovered
Part I a few days after I bought
Tango In The Night (of course I still like
Part II haha). When I finally heard both parts together, I was simply really happy and impressed. That bridge of keyboards and guitar between both parts is simply amazing, gives an amazing sense to the union.
And
You & I Part I is simply better than
You & I Part II. Is just a masterpiece, as you say!!