I've not started IMC yet, but did a lot more than the standard instrument training for PPL. I used foggles for a fair bit of the training and didn't get on with them at all. They dug into the side of my head, giving me a headache and making me feel unwell. Plus, as has been said, it is possible to see the ground with peripheral vision. I ended up sitting at an odd angle to prevent this, which was a pain in the neck (pun intended).