I'm currently running an ABA block with the 1.8l head on my car with an Autotech 270 hydro cam, and I must say that the cam is pretty good. I've heard from many people that the Autotech and the Neuspeed 272 are pretty much the same, but that the Autotech doesn't last as long. With the 276, my guess is that your gonna get a lumpy idle, lose a bit of low-end, but probably gain it in the top-end (logically). As far as improvement, I can't really tell you how much of a difference it's gonna make. Try talking to vrsik, his bro has an ABA with the 276, if I'm not mistaken. Also, are you running an OBDI or OBDII ??? The OBDII doesn't like to be modified cuz of the whole pollution control crap. If it is an OBDII, expect your car to run really ****ty on idle, even stall frequently...The problem can be fixed, but $$$$$. If you're running OBDI, then you shouldn't have a problem. I say go for it, if the price is right of course, the 276 shouldn't be too agressive and the car should retain its drivability...
That's my 0,02$...