I am interested in getting a new router to replace my old NETGEAR Router WGR614v10. So far, http://www.amazon.com/TP-LINK-TL-WR841N-Wireless-Router-300Mpbs/dp/B001FWYGJS/ref=sr_1_1?m=ATVPDKIKX0DER&s=pc&ie=UTF8&qid=1408037101&sr=1-1 has caught my attention. But I am reading reviews with updates to DD-WRT. What is that? Some sort of firmware? Would it be complicated to update?