That Kerry team were beaten in 2002, 2006, 2008 & 2009 by Cork. Several of the times they beat them it was close, with a couple of replays. Not exactly a 'handy run'. In any case how many times did we hear that Dublin's run was "too handy" and didn't prepare us for much harder games? Does this not apply to Kerry too then, according to those who keep the mantra about "handiest run"?
Dublin having 'too handy a run' in 2014 was often stated as a major reason we blew up against Donegal. Whatever about players 'preferring the handier run' in the province, the vast majority of evidence suggests that more competitive games are better (as long as you win!). Against that, too many very competitive games can leave a team tired, which I think happened to Donegal in the last few years.
That said, Tyrone managed the longest, hardest run to an All-I in 2005, ten games.