I have a pair of YSS shocks on my GS,bought them last year and have been very pleased with the improvement in ride quality.
My originals had nearly 60,000 on them and although they were not leaking the rear was really struggling 2 up.
I bought mine from Firefox Racing who were pretty hopeless,long wait,wrong rear shock sent,adamant it was the correct one and told me I must be fitting it wrong (it had the adjuster on the shock body instead of remote),no return of phone calls or emails,no apology or refund of return postage,won't be using them again.
The YSS shocks seemed very well made and fitted easily once i had the right ones,hopefully they will last as well as the 17 year old originals.