Well, we've made our choice. At this stage we will be beginning IVF in my next cycle, with preliminary treatment starting next Tuesday.
In the end, it wasn't a real hard choice to make. IUI sounds a lot less invasive (we just put washed sperm into you), but it does involve taking hormones every month, with some pretty harsh side effects. There's an increased chance of multiples (not at the moment, thank you) but a relatively low chance of actually falling pregnant. The insertion of the sperm doesn't sound like a picnic either - and with a lower chance, we'd probably have to go through it a few times at least.
IVF isn't great the first time. There's a nasal spray, injections and then the egg retrieval under general anesthetic. It will mean some significant time off work. But, the chances of falling pregnant (and carrying the baby through to birth) are significantly higher, and we're only going to choose to have one embryo implanted (common practice in Australia these days) so less chance of multiple birth :) . If it isn't successful the first cycle, we'll have had the embryos frozen, and latter cycles would be a lot simpler for both of us.
Considering all things, including our collective mental state, our comfortable financial position and how long we've been trying, IVF seemed the obvious choice. It won't be pleasant, I'm sure, but thankfully we're in a country where this is possible, and the science is good, and we have the means to be able to make this choice first. Most importantly, it's a decision we've made together, and one we're comfortable with.