Which should it be. I may have a buyer for my M&P40, which would leave me with enough money to buy the $300 (or more depending on the source) lens. Of course I want the 50mm f/1.2 but it's over $1500 and I just can't come up with that kind of money. Is the 1.4 a LOT better than the 1.8? I may decide to shoot pictures in bars and other poorly lit areas. Will it really make that much of a difference? Enough to justify the extra expense?