I bought mine from Ebay used it once and sold it back on Ebay. Here are the three reasons I didn't like about the G4:
1) the constant vibration on the suction side. Will this vibration cause a leak on a pipe fitting?
2) The warranty notes caution about using it on a vinlyn liner. Over time the print could wear off or tear if liner is old
3) I have two fiberglass steps that lead down into my pool and the cleaner doesn't clean the steps, so I have to still take out the pole and do the steps manually.