I did a clone of my drive before updating to 10.10.2 (it took about five minutes to update a clone from yesterday).

I updated from 10.10.1 via Software Update – a 550 Mb download.

Then I cloned the new 10.10.2 system to my previous clone: it copied 3.38 Gb of new/revised files and took 28 minutes.

Must be a fairly extensive update!

(edit) Also, it would appear that you cannot apply the 10.10.2 combo updater to 10.10.1, only 10.10.


iMac (19,1, 3.1 GHz i5, 12.7.4, 40 Gb RAM); MacBook Air (1.8 Ghz, 8 Gb RAM, 10.14.6, 256 Gb SSD) Vodafone router and Devolo Wi-Fi Extender, Canon TS8351 printer/scanner.