I am already kinda staking 3-4 coins and they run stable...its just the though that when i run into sum other 5-6 new coins this year.....I wanted a separate machine and not put all my virtual cash on my local PC, rather put it into a standalone system..... though you are right if the blockchains are synchronised an old PC works fine, but my experience is with only 2-3 coins and am planning to have atleast 9-10 in total this year....can't stick with one