the company i worked for paid us to install deca's at the same rate as a whole new receiver, and only $5 for wireless. so if the coax was going by the router, why not make some more money for a better connection anyway. i was never a fan on directly connecting a receiver to the router because if something happened to that box, the rest of the receivers would no longer have internet. only really a problem when using genie/HD boxes or just HD boxes. in a pure genie setup it didn't much matter, but you never knew when someone might swap a mini for a H25 and i didn't want to have to deal with some non-sense service call later.
FWIW using the 5g wifi with 2 bars or less almost never worked well, so if thats the case use wired or 2.3g