Based on the evidence one should avoid cap-weight, provided you maintain good control of the fees+trading costs.

I currently have a large chunk of my portfolio in QQQE, based in part on conversations on these boards.
However...

QQQ has outperformed QQQE by quite a bit since QQQE inception (2012-03-21):
QQQ -> 457%
QQQE -> 294%

Also, QQQ has outperformed QQQE in 73.8% of rolling years (252 trading days).
The mean outperformance is 2.5%/yr
Median is 2.3%/yr.

Question for Jim :), or anyone else who has thoughts.
* Would this be accounted for by valuations? Perhaps on 2012-03-21 QQQ was undervalued compared to QQQE, and now is more richly valued?

I believe Jim has been a proponent of QQQE vs QQQ, and I believe sees better current valuation metrics for QQQE.

Just to note that the two can have wildly different daily performance, I'm sure people noticed that Monday daily return was
QQQ -> + 0.03%
QQQE -> + 1.80%