Just did a quick speed comparison between the stock browser, fennec nightly 17.0 and Qt based Fennec. I loaded the site "www.finanzen.net" and measured the time. After doing this five times and averaging the values I got the following results:

stock browser:
Loading Time (average): 18.9 sec
Standard deviation: 0.4 sec

Fennec Nightly 17.0:
Loading Time (average): 26.1 sec
Standard deviation: 1.3 sec

Qt based Fennec:
Loading Time (average): 18.1 sec
Standard deviation: 1.0 sec

Therefore, Qt based Fennec is about 4% faster than the stock browser and about 31% faster than Fennec Nightly 17.0. Compared to the store version of Fennec, the speed improvement might be even higher... Good job!!!

By the way, does the Qt based Fennec version have something like a cache? Prior to loading the website I deleted the cache in case of the stock browser and in case of Fennec Nightly 17.0. However, I haven't found such an option in case of Qt based Fennec.

Edit: Maybe I should have also mentioned that my N9 is running PR1.3 @1,2ghz and FasterN9 1.14!

I just got some more results from Ringmark 1.4.0 (http://rng.io/)

stock browser:
Ring 1: 37 failed / 94 passed

Fennec Nightly 17.0:
Ring 1: 13 failed / 134 passed

Qt based Fennec:
Ring 1: 12 failed / 137 passed

So, Qt based Fennec wins this competition as well!

I also tried to run Browsermark 2.0 (browsermark.rightware.com) but unfortunately it crashes using fennec browsers. Using the stock browser i get 948 points, which is a rather bad results I guess...