The ASUS SABERTOOTH Z77 is a top mid-range motherboard, meaning it is targeted to the user who wants more features than mainstream motherboards provide, such as three PCI Express x16 slots and six USB 3.0 ports. The plastic cover that hides most of the motherboard, as well as the slot covers, is a feature that will make its owner feel like he or she has a unique motherboard.
However, the SABERTOOTH Z77 has some specs that make it closer to mainstream motherboards than to its sisters, the P8Z77-V PRO and the P8Z77-V DELUXE. It has a simpler voltage regulator circuit, no Wi-Fi, and lacks a PLX switch chip (that allows higher performance when several data transfers are being executed at the same time). The Realtek ALC892 audio codec is also a better option for mainstream motherboards than top-shelf ones.
In summary, the SABERTOOTH Z77 is an excellent motherboard, but unless you really like the plastic cover, you should pick the P8Z77-V PRO, which is a little less expensive and has a few more features, or the P8Z77-V DELUXE, which costs a little more but offers a lot more.