First off, I am very happy to see some actual innovation in the browser market.
Opera was the best a while ago with smallest resource footprint and fast browsing experince.
Today, most browsers kind of feel the same and this is a very welcome direction.
Being a heavy computer user all day, I find that soft tones are the easiest on the eyes and with that in mind, I would like to propose you provide some themes with more pastel coloured backgrounds. Gray colour especially looks slick and is easy on the eyes + matches with most other colours etc.
Also, for those people that do not identify as gamers, maybe a more mature UI language would be welcome (an alternative theme). Something that strives for elegance rather than an aggressive gamer look and maybe a more compact look while you are at it.
The "Limiters" are great but take up too much space and can maybe be made to look more elegant so your workspace does not feel like race car and so you dont have to scroll down to see all the meters.
Thank you and best of luck!