The best replacement for g5 is g6.

The best alternatives to g5 are rated as following:
★★★★★  g6
★★★★★  mx518
★★★★  g10
★★★  g500
★★  g4
★★  g9
★★  g7
★★  g3
★★  etha
★  mac pro
★  cobalt
★  gh2
★  copperhead
★  i5
★  g10 irons
★  g6 pontiac
★  deathadder
★  g2
★  razer copperhead
★  gh3
  epl5
  imac
  rapture
  callaway upro
  chevy cobalt
  gx1
  intel mac
  palio economy
  atmos
  rage
  g9x
  atmos raw
  opteron

Your alternative for g5 is not listed? Suggest!
Speaking about g5, one probably shouldn't forget about final cut pro.

Other search terms related to g5 and their ratings are:
★★★★★ final cut pro
★★★★ snow leopard
★ logic 9
You have in mind a companion for g5 and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of g5 in all years. Click on graph for more.
g5
g6
mx518