If you doing motorway miles, then the ed30 wont disapoint you. she will easily do mid 30's on motorway trawls. The GT is a totally different car, and cannot be compared as a simular car, because it isnt in the slightest. Either Get the ed30 which is what i wished i had before buying 2 previous Normal MK5 GTi's (reason being dealers back then wanted too much more £, so i settled with another standard one). Couldnt find the funds until one appeared as a private seller 14 months old, and secured the deal at £18.5k. Sold back my 3 week old steel grey GTi to get the ed30 instead. Much better car and love it to bits. Go with your heart ifti, if you can save a couple of grand , get the ED30, but dont panic if 19k is abit of a stretch, just keep looking and wait for a 5 door dsg to come along.
IT WILL EAT YOU EVERYTIME, when your in your GT golf. dont do it, be patient , one will appear for less money.