Originally posted by nimzo5
Take the pawn and learn from each game.
Agree with this.
If 1...e5 is your main response to 1...e4 you're definitely best off learning the most critical variations. I think Fischer's recommendation is still the main line, which definitely gives black an advantage:
1.e4 e5 2.f4 exf4 3.Nf3 d6 4.d4 g5 5.h4 g4 6.Ng1
Never underestimate the KG though... classic (or maybe a "modern"?) mistake really. It's an extremely sharp opening and seemingly benign moves can resonant quite loudly. So tread lightly.
Probably not worth it to learn a lot of lines though... You'll see the KG a lot less than the Ruy, Giuoco, or Scotch.
Just don't obsess over holding on to the extra pawn and you should be fine... Your top priorities should always be king safety and the initiative,
followed by material considerations. If you're given the opportunity to return the pawn for a comfortable game,
don't be a miser, let it go!
If you run into the KG in blitz however, it's probably best to go 2...d5 as it offers more opportunity to seize the initiative early in the game.
Actually I take that back. Just do whatever you want in blitz as everyone plays rubbish!