Alloy sprockets on the street?

I'm going to a 520 chain and 15/43 in the near future and I can get this for $230 AUD at my door.
http://cgi.ebay.com/ebaymotors/ws/eBayI ... AMEWA%3AIT
I like free power by doing things like using a nice light alloy sprocket. But a few people have told me that alloy sprockets over heat, get soft and chew out on long trips. I am planning to ride my scoot to brisvegas on my next holidays but I don't want to get there and find my rear sprocket a toothless wonder.
Anyone had this happen to them
http://cgi.ebay.com/ebaymotors/ws/eBayI ... AMEWA%3AIT
I like free power by doing things like using a nice light alloy sprocket. But a few people have told me that alloy sprockets over heat, get soft and chew out on long trips. I am planning to ride my scoot to brisvegas on my next holidays but I don't want to get there and find my rear sprocket a toothless wonder.
Anyone had this happen to them
