The metric which I think is most representative of user experience is first paint time. It measures the time from start of navigation (user clicking on a link, or typing a URL in her address bar) to the time the article text appears on screen.

We don't have measurements from January 1 - 14 for this metric.

The median first paint time from January 15 to March 31, 2015 is 1395 milliseconds.

Time-series graphs of this data are also available at http://performance.wikimedia.org/ .

The query I used to get the data was:

SELECT
  `event_firstPaint` as `firstPaint`,
  UNIX_TIMESTAMP(`timestamp`) as `ts`
FROM NavigationTiming_10374055
WHERE
  `event_firstPaint` > 0
  AND `event_firstPaint` < 60000
  AND `timestamp` > 20150100000000
  AND `timestamp` < 20150401000000;

The total number of samples is 13,780,175. Each sample was measured client side (i.e., on the user's browsers). We log timing measurements for 1:1000 page views, but not all browsers expose first paint timing data. The average number of samples per day is 1410.

The median page save time from January 1 to March 31, 2015 is 1987 milliseconds.

The query I used to get the data was:

SELECT
  `event_duration` as `duration`,
  UNIX_TIMESTAMP(`timestamp`) as `ts`
FROM `SaveTiming_10785299` -- and SaveTiming_10077760
WHERE
  `timestamp` > 20150100000000
  AND `timestamp` < 20150401000000;

The total number of samples is 23,728,230, representing all edits made with the wikitext editor during the quarter for which a client successfully submitted a measurement. (A client may fail to submit a measurement due to connectivity issues or ad-blocking filters which target EventLogging's URL endpoint).