This gambit is terrible, as I've already written several times.
I played in a tournament (The Englund Gambit Open) and found that it is extremely difficult for black to get even a draw.
I avoided always the "main lines" which involve white playing Bf4 and black playing Qb4+, Qxb2, etc, but I've heard even that those are extremely simple positions for white to play.
EDIT: I've always been a fan of the line ending in Qc1#! It's just that white doesn't seem to fall for the tricky stuff, at least not here on chess.com. I think that a gambit should offer at least something other than a couple of tricks. I don't think the Englund does that.
This gambit is extremely obnoxious and dangerous if white plays incorrectly. I have used it in blitz numerous times and so many fall for one of the numerous traps. However, if white and even black can avoid the pitfalls, they should be well off.
After d4 e5 dxe5 Qe7 Nf3 Nc6 --------
White should in general not play Bf4 to protect the e5 pawn. Instead, Qd5 can be played if white wishes to hold on to the pawn. White can also just give the pawn back and consider rapid development since black's Queen on e7 is slightly misplaced.