Yes, We lived in Oz for almost 24 years as PRs prior to leaving in 1993 with 5yr RRVs (for personal reasons; all substantial). Through circumstances boc, we were unable to return permanently during that time, so returned prior to expiry and were granted further 5yr RRVs. Ours is a long story, so won't tell all here, but in the 18 years between our first departure from, in 1993, and our last trip to Oz in Oct 2011 (when we applied onshore for PR -- successfully, after a nail-biting eight months, having met all DIAC's criteria and proved extensive close personal/cultural ties to Oz) we made 15 visits to our extended family. When we went to DIAC in Currie Street to have our passports issued with new RRVs, we were told (and the officer turned his computer monitor around so we could see for ourselves) that upon our return to live in Adelaide (which we intend doing in approx 18 months time, or earlier, depending upon how long it takes to 'shut up shop' in England), we will be eligible to apply for Citizenship 2yrs 8mths from our arrival --- having calculated the number of days and nights we'd spent in Oz during those visits.
I've kept this as brief as possible, so hope I've adequately explained the important bits, so it all makes sense.
Still, if, when we do go back to Oz, it turns out DIAC were wrong, well, no worries; we have no plans to leave again.
All the best,