I went grain free/Paleo when I had to go low-iodine - it just kind of made sense. It was rough for the first bit. I was craving carbs like crazy (apparently this is normal - our body gets used to burning carbs for fuel and it takes a while for it to switch to burning fat instead). I am now grain-lite - I will eat a little rice or masa harina once or twice a week. If I bake, I use coconut flour, almond/other nut flours, tapioca, arrowroot and potato starch.
I feel pretty good without grains. I don't get bloaty after meals, even big meals. My sugar cravings are greatly diminished (though I have also cut out refined sugars so that makes sense). My digestion is great on account of all the vegetables I eat. (I eat MOUNTAINS of veggies daily).
Beware when starting Paleo: a lot of people start out just eating tons of meat and nuts. I did this in the beginning and felt just ugh. It is not Atkins, where you eat only meat and fat! You need to include lots of veggies.
Sample menu (this is what I ate yesterday):
red cabbage braised with apples
homemade sausage patties
almond flour biscuit (my adaptation of the bun in the bowl - still a work in progress)
tea with hemp milk
celery sticks with almond butter
1/2 avocado with lime juice
homemade beef stew
roasted carrots and parsnips
So everyone will be a little different - it depends on what your goals are. Those trying to lose weight will want to limit the starches. Those trying to add weight will want to up the healthy fats. I am fairly active and my weight is fine so this amount of food works well for me. I also have found that my weight is much more steady grain free. The more grains I include the quicker my weight tends to creep up. Without grains I rarely step on the scale. If anything I tend to drop weight really quickly when I eat totally Paleo.
When I no longer need to eat LI, I will be having dairy again. I miss cheese!