I'm not sure what you mean by "Tablo on wifi is not that great". The whole point of Tablo, as I understand it, is for the client / player devices to be on WIFI.
My Tablo is hard-wired to the router / WIFI access point, which is maybe a foot away. Our player devices (Android phone, Android tablet, iPhone) move around the house as desired. So there should be no problem communicating between the Tablo and the WIFI access point. Any WIFI problems are from the access point to the players.
My access point is an Apple Airport Extreme that supports 802.11 a, b, g, and n. My understanding is that Tablo also uses 802.11n, so there's no point in upgrading the WIFI to 802.11ac, at least not for Tablo.
I have thought about upgrading to a WIFI mesh network, but since I can't tell whether my problems are due to the network I'm reluctant to do so.