I take it you mean a router, The Hub 3 provides the Modem function of modulating and demodulating the internet singnal
A third party router will not improve wired speeds you are getting from the Hub whilst connected directly to the hub by ethernet cable.If you are not getting full speeds whilst wired directly to thehub, then you have a local circuit problem that needs to be resolved by VM and a new router will not help.
However, a decent third party router will provide a better wireless coverage.
Whether you will get better wireless speeds will depend greatly on several factors, mainly what wireless clients you have.
For exanple a wireless N adapter that is only capable of using one wireless stream will only get about 35 to 40 Mbps on a single wireless channel.For greater speeds you wil need wireless MIMO clients capable of using multiple wireless streams, preferably on the 5Ghz band, so you can use channel bonding with a greatly reduced risk of interference. Or, for the best speeds wireless AC wireless clients. You will need to use wireless AC to have a realistic chance of achieving 200Mbps, a decent MIMO wireless N wireless adapter should get fairly close.
Asus routers are well thought of and should give you a better wireless coverage, but how much your speed will improve will depend on your client hardware, range, interference and the topography of your home.