Took delivery on my Smarthub today. My Homehub 5 was working fine but I was offered Smarthub free (except for postage) so though it must be better. My Infinity speed is reaching 50 m download.
The experience has not been good. It works fine on LAN but the wifi 2.4 signal is very poor from my upstairs study to my sitting room downstairs. I have performed resets and restarts but my Amazon fire box reports a very poor signal and will not work. I am pretty clued up on these things and have had several BT hubs over the years. Enen my iPhone 6 was stuttering.
I have reinstalled my Homehub 5 and all is well. I will have another go with the Smarthub when I am feeling stronger.
I might try splitting the 2.4 Ghz from the 5 Ghz just in case it is trying to use 5 Ghz downstairs and getting a weaker signal. It probably shouldn't make any difference but it might.
I've had a few issues on 2.4Ghz with an iPhone 5C and Samsung S4mini about 6 meters from the HH6, but my Motorola was solid on 5Ghz at exactly the same time.
But compared to my HH4 signal strength, both 2.4 and 5Ghz has improved a little all around the house.