Sp00kY, shoo~~~ go play with ur 5D M2...LOL...
These kind of price now, who will want to sell?
If you're new, go on P.
Then learn when u need to use A and S.
As for using M, if you have certain things in mind which is not achievable by using either A or S, only use M.
Using M doesn't make you an expert, nor does it show you're a better photographer.
I have to disagree with you to a certain extent.
First of all, the sharpness of the 1.8@1.8 is sharper than the 1.4 (be it D or G)@1.4.
As you stop down to F/2.8, the 1.8 is still sharper than both the 1.4 in the center, but on the corners the 1.4 does better.
Again as you stop down to F/4, the 1.8 is sharper than the 1.4 in the center, but loses out at the corners.
The reason for one not being able to get a sharp picture with a 50mm F/1.8 is the user problem and not the lens issue.
I've had friends who had taken stunningly sharp images with 50mm F/1.8s at 1.8 wide open, even i sometimes do that myself when i really need F/1.8.
Just remember, the DOF at F/1.8 is really shallow, a lot of times you don't get it sharp because of the shallow DOF and not really because the lens ain't sharp.
lol... den i have to blame on my noob skill...
but itz jus my suggestion...
Nowadays so active in D90 thread, wanna join D90 thread soon enough la this fellow.

hahah... i m trying to scout for any cheap price oni la... haha... no money aso....