Opening for Black against d4

@ThrillerFan, thanks a lot. The whole thing is really based on trading the DSB, I suppose. I haven't looked deeply into it yet, but I'll certainly start checking the 1. d4 Nf6 2. c4 b6 3. f3 Nc6 4. Nc3 e5 5. d5 Ne7 6. e4 Ng6 lines.

It is not so much the "oh, it is drawish at move 3" stuff you see with the Exchange French.  Rather, it is later in the middlegame when all the pieces get sucked off the board and you end up with a symmetrical structure with 1 heavy piece each.  There were just too many of those lines that White can choose to go into and it was annoying having to try to outplay people in long endgames after a long day at work.  That said, there is nothing wrong with that repertoire - I just wanted to add something with a bit more complexity to my repertoire for when I need to fight for more.

Is the route to this simplified ending easy enough for a 1600 player playing White to reach?  Or are we assuming White is playing 20 strong moves first?

I ask because lines like the 13.Rc1 line of the Mar Del Plata Kings Indian scare the bleep out of me when I face players with a rating that starts with a 2.  A 1500 player?  Uhm, 99.9% of them probably don't even know how to get to that position, and if they do, they surely have no clue about the ins and outs of 13...Rf6 vs 13...a6 vs 13...Ng6.  It is the 2100 players I face that play this line that kills me.  And this is nothing new.  I have spent years looking for an answer.  I rarely ever face it OTB, but once you start playing Correspondence, it seems to literally be all you face.  This is the main reason I have been drifting back to the Nimzo, which I played years ago, rather than the KID.

I did not think so at first, but when I had 3 1500-1700 players go into the exact same line in the same event, I was a bit annoyed.  I did not find out until later that they all had the same coach (an FM) who gave them a repertoire to study, so I'm not sure how much I would run into it elsewhere.  However, since I play these kids fairly regularly, I wanted something I could use that they likely would not be as familiar with.

Well, since I'm basically just getting back into it after years of a "Nimzo-Hiatus", I'll probably just go for the Repertoire at first and then expand like I did the French.  The French I could play almost any variation and know what I'm doing.  By choice, I don't ever play 3.exd5 or 3.Nd2 as White, but not like I don't know them.

Also, not like I'm picking up the Nimzo for the first time ever, so the time it takes me to absorb that book will be light years less than the time it would take to absorb it had I been playing the Nimzo for the first time.  I've read parts of the Dearing book in the past (4.e3 b6), and Tony Kosten's old book "New Ideas in the Nimzo-Indian" and the old red book from 1995 on the Rubinstein Variation and some of the Everyman books from the early 2000s that came out before Dearing's repertoire, so picking up additional lines won't take me for ever.  I still know all the general ideas.  It's more the specifics that I need to refresh myself with.  Like a Java programmer learning C# (C-Sharp, a .Net language) as opposed to an Interior Designer learning how to write computer code.

Do you have the grandmaster repertoire book on the Nimzo by Michael Roiz? Know how it compares to Dearing's?

Just don't try to take a Java programmer (or anyone who learned with managed languages for that matter) and try to throw them into something that requires C/C++

I have Roiz's book and use it for reference regularly.  The main problem I have with using Roiz's book to base a repertoire around is that he did not try to come up with consistent structures.  Instead, he went with the sharpest mainlines.  For example, he goes for 4... d5 against the Capablanca Variation, and goes for 4..0-0 against the Rubinstein (and even recommends 5..c5 against White's 5. Qc2 - meaning a transposition of move order leaves you with a completely new position).

The annotations and lines are perfectly fine, but unless you are a professional player, there is a lot more to learn from his approach than to take an approach of finding similar structures to play in (which is the approach Sielecki took in both his Nimzo-Bogo book and his Nimzo-Ragozin course on Chessable).

No I do not own the Roiz book.  Only Nimzo Book I own from this decade is the Everyman one from 2015 and things like NIC Yearbook articles along with all of those pre-2005 books.

I did Pascal (write, writeln, read, readln) C, C++ (cout, cin), Haskell, SQL, and Fortran in college.  Basic and COBOL in highschool.

I play French against e4, luckily got French repertoire for black by IM john Watson on ICC. The way he introduce French allowed me to feel comfortable as black even though I know I won't be mated in opening against any 2000+ , he covered everything. I am a beginner though. I was 1200 but after taking his lectures I reach 1500 in less than two months. I am very confident with French and I felt how important opening is. I don't know much more abt theories but I am good at memorizing various lines and setup. All I want a weapon for black against d4 so I can work on it. Em playing Slav these days but often times white play London system or trompsky like things. I need a opening which can be play various d4 openings. In short something like french, But Thanks much everyone! 

C# is also managed, and very much inspired by Java. Though I knew Ansi C and C++ when I had to learn it.

Recently I've been playing Budapests and some all purpose "d6 against everything" system (which offers me a playable middle game, this is all what an opening should give you. Haven't tested it against the club d4 players who give me trouble yet because of quarantine though).