I don’t have one yet, but here in the UK I think it’s not a bad price. I already pay my network about £25 for call minutes and 100 sms, plus £7.50 for unlimited-not-really data over 3G (which to be honest, and with a useless browser, doesn’t seem much faster than Edge with Safari), and £10 for unlimited-oh-yes-it-is-oh-no-it-isn’t use of T-Mobile Hotspots on my MacBook and iPod touch. I’d save money on the O2 deal but I’d have to use the crappy Cloud wifi network, on the phone only, and I wouldn’t have the option of using my phone as a bluetooth 3G modem for my MacBook (sometimes handy, though only to ubergeeks like me).
If I could justify keeping the Hotspot account alongside the O2 contract I might jump now. Otherwise I’m really hoping for more network choices. Given voip on an iPod touch and a few other upgrades to come, I might just dump the networks entirely.