It's been used by one of my friends for a long time (I am the stringer for him) and it has been pretty good. Durability was averaged in about 30 hours or so for him.
Thanks BlueJeff, In your opinion which string in the Yonex line would be comparable to the GS80? Thanks.
I've tried it and it is quite durable. The only thing I did not like was that it starts to lose tension significantly before it breaks. So I end up cutting the old string to have it restrung again. The Gosen Pro70 would be a better option.