Just tested it, and not impressed. The installation is tricky, to say the least. Even though I followed all the instructions, it would not read my profile, so I ended up doing system restore. And then Firefox would not start. Ended up re-installing the official Firefox build, but at least it read my original profile.
For the few minutes that it actually did work, it did not speed up surfing noticeably. Mabey by a few fractions of a second
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Found this thread, with lots and lots of Firefox tweaks.