I would choose the GSG over the Ruger. I love Rugers with the exception of the MK series. Ever try to assemble one after cleaning? A nightmare! I've fired a GSG but don't own one yet.I have Ruger blackhawks, Vaquaros and single sixes and love these guns but will never have another MK series. I do enjoy shooting my wifes Colt Match Target Woodsman(3rd generation)
i've owned both guns and hands down the ruger is far better. the gsg is light and cheap feeling with "knock off" style and materials that seem almost toy like. although the ruger has the reputaion of being hard to disassble i guess it matters who you are. my personal range results after 2000 rounds with both --the ruger a tack driver and the gsg just tacky.