You are right that persistence is the requirement of the moment, and is the big downside of the B. But lets be positive...
1. The B will probably be able to get much closer to the action than the other types because of its reduced reliance on big smooth tarmac. Thereby cutting reaction times, as well as transit fuel burned.
2. For the current types of ops stealth probably isn't such a big deal. The B will be able to add a couple of tanks, which should make a big difference to that 450 combat radius.
3. 450 isn't so shabby, but more is obviously very attractive.
4. I hear that there is some pressure in Australia for them to split a small part of their buy and get some B's for the LHDs. If we give Canada a similar nudge in that direction the CVF could alternate hosting a 'commonwealth squadron' on deployments. That would take pressure off our own units, keep the carriers topped up and be a great
pr exercise. I'm sure they'd also make a great contribution. The B version makes this kind of exercise very easy.