SteelSeries' original Sensei mouse featured a 32-bit ARM processor that allowed it to double up laser sensitivity to 11,400 DCPI (double counts per inch), which is one of a handful of amenities that added up to a $90 price tag. That's not terribly obscene for a gaming grade mouse, though it is on the higher end. If you can do without the 32-bit ARM chip, SteelSeries is now offering a slightly stripped down Sensei [RAW] model for $30 less ($60 MSRP).
The Sensei [RAW] also does away with the LCD menu system and onboard memory, which could be deal killers if you're a frequent LAN party goer always on the move. Otherwise, it's essentially the same rodent. It has 7 programmable buttons, a braided anti-tangle cord, three zone illumination, and 90-5,670 CPI.
There are two versions of the Sensei [RAW] to choose from, including one with a glossy black surface, and another with a rubberized coating. Both refrain from playing favorites with right- or left-handed gamers and sport an ambidextrous design.