Looking through the most recent pages of this thread (462, 463, 464), I see people chatting/commenting about the new Hub 3 being extremely unstable and also very awful to deal with in terms of general usage and heavy usage, I had similar problems with the Superhub 2AC (which I got free of charge when getting my 50 to 70Mbps upgrade in October 2015).
Firstly, I had a problem with my ping time / latency time fluctuating, which was very minuscule, but me being the tech-savvy guy that I am, I couldn't help but notice it.
Basically when playing Call of Duty on PS3, XBOX 360, XBOX One and even a game such as Counter Strike on PC or something, I would continuously get lag spikes of up to 300ms+ for no specific reason at all. Because of how I set all my network up, I usually get host on games like Call of Duty on both PS3 and XBOX 360, which proves my connection is decent! However at intervals during the game when checking my connection and/or stats in game, everyone else would sometimes drop down to a red bar as a result of my connection being host due to the lag spikes. Also one more thing, sometimes (but not all the time) I would get host booted from a match while being host for no reason at all, other than the lag spikes and my generally bad ping/latency times due to the Superhub 2AC. It bugged me so badly, to the point where I tried it in modem mode and I started having really serious issues with double NAT (I will discuss this below).
Secondly, I had a problem with STRICT NAT type on XBOX One (which happened on both router mode and modem mode) and I tried the following things to solve it:
- Tweaking and tampering with the firewall settings
- Disabling the firewall completely
- Assigning all gaming consoles in my house to the static IP address table
- Taking use of DMZ (which my PS3's static IP address was initially assigned to), so I switched the DMZ IP address around to the XBOX One's static IP address)
- Port Forwarding and Port Triggering, etc. (I shouldn't need to do this, if the firewall is fully disabled anyways, however I went ahead and tried it - however I got no luck from it in return).
No matter whether I used normal router mode or modem mode on the Superhub 2AC, the XBOX One would still end up with a damn STRICT NAT type. And also before anyone says "did you try using the XBOX One plugged directly into the Superhub 2AC via an Ethernet cable?" - the answer is yes, I tried using a CAT5e based Ethernet cable when the Superhub 2AC was in router mode and also when it was in modem mode (I tried plugging it directly into the modem, excluding any router in-between the XBOX and the modem, which by my knowledge should theoretically automatically set your NAT type to OPEN, thus unlocking/unblocking all ports).
Luckily, since when my 70Mbps upgrade came along I opted for self-installation, which means I didn't get my Superhub 1 taken away from me by an engineer/technician, so I phoned VM up and asked them if I could switch back over to my Superhub 1 and they did it for me with no other questions asked. I know the wireless sucks on the Superhub 1, but I now know the modem in the Superhub 1 is a lot more stable than the modem in the Superhub 2AC. I have a few problems with NAT types every now and again, but that's only when I have more than 2 or 3 gaming consoles connecting to the internet at the same time (I have 2 XBOX 360's, 1 PS3 and 1 XBOX One in my house), which is highly understandable.
I was just very tired and half asleep, haha. Sorry for that. 
