I had an ironic state of play with Yodafone when I switched across recently: after having been on the network for 3 days, I noticed signal was poor to nonexistent in the study where I work. Recalling that the Access Gateway was free to new users with a tariff over £15/month (not just the £160 flat-rate mentioned in this article), I asked for one free; yodafone tried to tell me that it should have been specified at time of purchase (when I didn't know how bad the signal was here!) and couldn't be bolted-on afterwards - a mere 3 days, "new" enough to be well within my statutory cooling-off period on the contract and yet not "new" enough for the purpose of an Access Gateway? "You'll have to return the connection and get a new one", with implied downtime.
Eventually, with some assistance from their twitter staff instilling sense in their customer services, they sent me one out. Having 3G around the house is a total bonus - both my other half and I benefit hugely from it now with blackspots eliminated.
There have been a couple of significant downtimes but nothing so huge that I couldn't use 2G instead. It's quite funny when you haven't noticed but get an SMS *after* the outage to say "sorry, something might be wrong with it".
For those questioning why: 3g uses far less battery than wifi and you can't route calls over wifi directly.