Queen's Gambit Declined: Modern Variation, 4...dxc4 OK For Black?

I'm not really sure what the correct name of this is because of all the transpositions that are possible but this is the position I'm not sure about:

In this position moves like 5.Nf3 and 5.e4 can transpose into other things but the move 5.e3 sticks out to me as something simple that White can play. So we know that if White plays 5.Nf3 a6 6.e3?! Black is doing OK because the knight is on c3 too early in this queen's gambit accepted position. But 5.e3 looks like it avoids this problem to me. For example after 5...a6 6.Bxc4 b5 7.Be2 c5 White can play 8.dxc5 which is something he can't typically do in similar positions because White hasn't castled yet. But what's even better here is that White's dark-squared bishop is outside the pawn chain.

So I'm wondering if I should play 4...dxc4. It almost seems like White's position is better than usual here. There's also the point that I wanted to play this move with the idea of complicating the position but it looks like White is able to avoid that with this move order.

All 3 moves 5. e3, 5. e4 and 5. Nf3 are correct. I guess that it's rather the matter of personal preferences and affinity with the position.

Now, white could play 5.e4 and regain the pawn and I don't think this is that active for black. But, as the game shows, white has various ways to play it slow initially and sac the pawn, only to strike back later. I don't think your own example works because you forgot c6. And if you do play c6 it's exactly like this game. 

This is Queen's Gambit Accepted by the way. Black accepts the c4 sacrifice.