i have a 15" macbook pro retina, late 2013.
i can only say that i had never used chrome before and stuck to safari for, well pretty much ever.
since the update to yosemite (and all the recommended updates), the lagging time on safari loading pretty much any web site (including macrumors) has been horrible. it gets stuck all the time and sometimes it takes minutes (yes, i timed it) to load a page, or it get stuck in the middle (bottom half is blank).
i finally downloaded chrome and its performance is very fast.
i am glad you guys have had good experiences, by mine has been horrendous.
i can add that i have in the meantime loaded chrome in a number of slightly older computers (all macs, with various versions of MacOS) at home and in every situation chrome works better than the last version of safari running on them.
i would like to run safari, as i am more familiar with it, but i might switch for good to chrome.
i still have safari as default, so sometimes i would be using chrome, then i click a link on a mail or something, and then i look at the site taking ages to load and i am puzzled until i realize it is bloody safari's fault. then i copy the address, paste it in chrome and I am using the site, while safari is still trying to load the same page