which is best adcom gfp 555,555mk2,565?


hi,my adcom gfp555 just broke no output at all,ive been looking on ebay and they have a 555mk2 but i notice on the back ther are not the mmand mc swithches on either the 555mk2 or thr 565,also i notice that on the 555mk2 there is no lab connection.i'm i better off staying with what i have?,the 555 is in the shop but i'm wondering are these other gfp's good enough or better to put my money in?.or can my 555 hold it's own against these other preamps?
tdor1997