The brand new Gigabit Ethernet card features four 10/100/1000T Gigabit Ethernet ports on a single card, giving you the opportunity to add even more ports to your router, and saving valuable PCIe slots. Bring maximum throughput and port density
to your device, and with PCIe - bus speed is no longer the limit.

this is very cheap compared to intel quad port, thumb =)

MikroTik RouterOS Version 6 Changes
Here is a list of some changes and improvements for RouterOS v6

• A new linux kernel is used (version 3.3.5) which enables us to use the latest drivers and support most of the latest hardware
• Simple queue mechanism is improved to greatly benefit setups with hundreds or thousands of Simple queue rules
• Simple queue performance on multicore systems is improved significantly
• Latest v6rc3 adds more Simple queue optimizations, Packet flow is slightly changed as you can see in the diagram below
• v6 also features fastpath feature - a mechanism of packet flow shortcuts to massively improve data throughput, currently this feature is added to simple setups, like routing, bridging and mpls, but in future we plan to enable fast path for more complex features, such as Firewall
• Fastpath is also supported for MPLS traffic since RouterOS v6rc3
• RouterOS is now made 64bit for TILE architecture, that is used on our new Cloud Core Router devices (see article on page 1), giving ability to use 16GB of RAM or more

Hidden Feature - Cable Diagnostics

The ability to detect cable problems has now been added in RouterOS v6rc3 and newer releases.
RouterOS will tell you:

    • Which cable pair is broken
    • At what length the cable is broken
    • How the cable is broken - torn or shorted
   
This works on SXT-G, RB711G, RB2011, RB750 series and other devices with the same switch chips, and also the new Cloud Core series devices.

Source