Agreed with above, nothing wrong with radweld, people just can't read the instructions 
Yeah just because you had no problems anyone who did is obviously too stupid to follow instructions properly

I will add that it did a good job of plugging the leaks on my rad for a few months, so gave me time to get a new one. Unfortunatly the side effect was a cold car, though it was in the summer so not all bad.
I wouldn't recommend it myself, as topping up your water for a bit then replacing the rad is alot easier than replacing the heater matrix. Not as if a good second had rad even costs a great deal!
Edit: forgot to add the real reason I wouldn't recommend it: when I took the head off I found most of the water channels thru the head gasket were clogged up with radweld

It doesn't help that although the coolant channels in the block are quite large, the holes thru the gasket are much smaller! After I replaced it the engine ran much cooler and heated up faster
