Queens Gambit vs Catalan

This has been a long standing question. What to start off with white?

The move order is known to everyone but still just to refresh:

QG: d4, Nf6, c4, e6, Nf3, d5, e3/Nc3/etc... (queen's gambit declined)

C: d4, Nf6, c4, e6, Nf3, d5, g3, dxc4(open)/ Be7(closed), Bg2...

So, what to play since the move orders are almost similar. Of course, it all depends on the move order. In some cases, it is not possible to play the catalan with the queen's gambit. 

But in general, if the move order is similar, which one should be preferred?

Both are excellent. I prefer Catalan.

Nobody can tell for sure.

Carlsen preferred the Catalan in the last World Championship match.

Whichever one you prefer and/or know how to handle better. They're both top-tier openings. There's no wrong choice here.

I play both and sometimes it ends up going to Catalan and sometimes when they accept the gambit especially, I just play the Queen's gambit accepted which usually is pretty good for white!