i know its a bit different as i have a vr6 conversion, but i've recently fitted a new solid front mount to mine.
the handling feels a bit more precise, gearchange is a lot better (5th was sometimes a pain) and i know the engine moves a lot less as it used to rub on the chassis leg when corning hard left (clearances are a bit tight) but now it doesnt.
apparently they can cause a bit more vibration in the cabin but i havent noticed any.