I have used it, I did the article on the UK site, It is tough stuff, and takes a bit of practise, the chaps at easyweld are helpful.
The main problem is getting it to bond to the aluminum casting, a stainless steel brush is used to continually clean the metal as you apply.
I filled a knackered tread hole on a fork tube, drilled it and tapped it out, works a treat, but it did take a few attempts,
Getting enough heat is also a problem, especially with large objects, I'm trying to fill a hole in a crankcase where a broken chain has damaged it (Probably why it was cheap), anyway I can't get it up to temp 'cos the whole casing hot.
If your in the UK drop me an email with your address and I'll send you a couple of sticks.