Several comments.
"less memory use is good" should be qualified. For a 2MB machine like used in your test ($50 of memory, a 2006 spec machine), your browser is still using 3% of memory in the system. I believe your test should have qualified the results: I want my browser to use *more* memory if it means higher speed and responsiveness, not less. Today, most of my memory is going spare anyway - use it, browser!
For your test environment, you don't specify the network you're running on. For a US-dweller, I run on a very fast network (I've trialed all the providers at my home, and chose Comcast over Uverse because Comcast has 13ms latency and Uverse has 23ms latency, at the same throughput). I have solid measured rates above 20Mb/sec, and call my provider if a test ever dips below 15mb/sec. Most US users have 6Mb/sec at best, and at work, often 1.5Mb to 6Mb is shared among many users. I also use a combination of Google's DNS service and another DNS service, not the default for my provider. I trialed all those, too.
We know Chrome aggressively pre-caches content and DNS requests, and likely had different thread tuning. These changes will give different results depending on your connection to the Internet. I would expect a European user with high last-mile bandwidth but large lag to the US to have even a different experience. These effects aren't minimal! And, if you're paying per-bit (like tethered over a cell connection) pre-caching might be a serious problem.