I'd really be interested to see how many times I've been nexted - either between logins, or perhaps on the defense log screen showing number of nexts since last defense.
As a th8 I've always hung out in gold3. When my base was weaker I seemed to do better on defense - and my theory is that this is because it invited lower level or less experienced attackers. Now my base is close to maxed, I get a lot more better quality attacks and fewer crappy ones, even with the same layout - so I am thinking that I am getting nexted a lot, just leaving the higher level or more skilled players to attack me.
perhaps the lesson is have a mediocre layout and defenses and just have traps waiting in the right place for the inexperienced. More likely to get a cheaper shield...