Just to make it a bit clearer....
It's not power that will kill the rods,it's torque.
The realistic safe maximum seems to be around 450lbs,and at or below that level,from discussing it with people who've run that for some time,the engine is reliable.
Mine runs around 440bhp and 420lbs,and has done so for nearly 10 000 miles currently,as an everday runabout.
Over on VAGOC,there are several build threads,including a good few cars running from 420 to over 500bhp...well worth a look if you're even thinking of going down this road.
Whatever you do,if you have the car remapped,an oil breather system is essential,as are oil and plug changes at around 5000 mile intervals.