The Czech Benoni

The Czech Benoni is a an opening I Have been playing for awhile now. May someone help me learn more ideas and strategies and lines behind it? One way to get to the Czech is...

1. d4 Nf6 2. c4 c5 3. d5 d6 4. e4 e5.

The setup seems to be similar to the Nimzo-Indian and some Dutch Variations. Thanks.

Game 3530846

Actually not the same but similar ideas.

Isn't the immediate e5 advance better than e6, then e5?

Well sometimes. I think it is simply a matter of taste since with ...e6 the postition is deemed closed. If white captures the pawn Black is considered "better."