I've recently had a speed-boost from 30meg to 70meg and was hoping I'd have luck in getting upgraded to one of the newer superhubs. I've had the superhub 1 for some time now and have always had trouble getting a strong wifi signal in the upstairs bedroom (I've even tried using a range extender with no luck!) and I know the newer hubs do the 2.4Ghz and 5Ghz bands simultaneously which should help.
I've had a look if I'd be able to do this online with no luck, and both times I've been on the web chat I've been directed to go and speak to another team so I thought I'd try asking here instead.
I would try ringing in and talking to Retentions (Thinking of Leaving Us option). have a friendly chat explaining how bad the wifi is on the now obsolete SH1. They should be able to upgrade you to the SH2AC or Hub 3 (I would go for the SH2AC). I would bear in mind it may tie you into a new contract, so it would be worth checking.