Horrible idea, It's considered a downgrade more than an upgrade. The SP only has a better GPU. Stick with the G for now, if you really like Sony, wait for the Xperia G to come out (a new mid-range phone) I own an SP but I wouldn't recommend buying it now, maybe last year but now, definatly not. Also it weighs a ton which is one of it's bigger flaws.
This phone is incredibly fast though and it only improved when 4.3 came out
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