QGD after 3.Nc3: 3...Nf6 versus 3...Be7 (Alatortsev)?

There are hardly any books I can find that give any more than passing coverage on the Alatortsev variation of the QGD ... all I can find are “The Queen’s Gambit Declined: A Grandmaster Explains” by GM Colovic (Chessable ebook) and “The Queen’s Gambit & Catalan for Black” by GM Janjgava, published in Y2K (Gambit).

The Alatortsev seems to simplify Black’s life so I would have expected it to get more press, yet I also recently came across a comment from an author (cannot remember, my apologies ... maybe GM Sadler?) that recommended developing players to AVOID playing the Alatortsev as Black in the QGD.

1. What are the merits and demerits of ...Nf6 before ...Be7 in the QGD?
2. Which move do you recommend a lower level or developing player adopt on move 3 in the QGD and why?
3. Why would a high level player recommend 3...Nf6 to developing players rather than the Alatortsev?

I would suggest 3...Nf6 because it seems to be easier to find advice on how to play the resulting game.

3... Nf6 allows the exchange variation with Bg5 whereas 3... Be7 does not. However, whether Black has better chances in lines like 3... Be7 4. cxd5 exd5 5. Bf4 c6 6. e3 Bf5 7. g4!? rather than the classical lines 3... Nf6 4. cxd5 exd5 5. Bg5 c6 6. Qc2 Be7 7. e3 0-0 8. Bd3 Nbd7 with either 9. Nge2 or 9. Nf3 is open for debate. 3... Be7 also limits Black's options after 4. Nf3 : after 3... Nf6 4. Nf3 Black can just play anything : Ragozin, Vienna, Semi-Tarrasch, Cambridge-Springs, Semi-Slav...

Huh? What if opponent just do the exchange?! Agree that the Anastovev variation seems to get little attention. Maybe has a difficult name. A popular alternative... try taking the exchange with the knight instead of pawn for a Semi tarrasch, or similar position.

Recently 3...Nf6 is the more popular option, partly because the Short varition is doing very well for Black (1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.cxd5 exd5 5.Bg5 c6 6.e3 Bf5!? 7.Qf3 Bg6 etc), and partly because of the difficulty white has to find some sort of an advantage in the semi-Tarrasch (4.cxd5 Nxd5) variation.

But- in the end, it's a matter of taste, both are good.

I rarely see 3...Be7 played against me, but I always play the 7.g4!? Botvinnik came up with whenever I get the chance. I've studied these lines a fair amount and I actually prefer the pawn sacrifice with 7...Be6 8.h4!? Black taking on h4 is very risky, but I love the sharp lines that come out of this as White and it helps that I've looked at them a fair amount. Sharp positions like these are places where opening study and preparation against a specific opponent can really pay off.

Thanks for the helpful comments everyone. Sounds like 3...Nf6 taps into a lot of theory, instructional books, and historical games, but 3...Be7 is also fine. I will continue the internal debate until it actually comes up OTB (I have faced 1.d4 only twice in roughly 35 rated OTB games where I was Black... the last time I got my queen trapped while transitioning to the Middlegame).