I've got about 2 minutes "spare" here, and ran into these photos; which I thought I'd stick up here. (Click for bigger versions- recommended)
This is what our "to eat" hazels look like these days; this is actually what we ship. The upper photo is of a loaded sorting tray, just as it is when we're doing the final sort, removing any weeviled or spoiled nuts we can find.
There's been a substantial change in the overall size and quality; as we include more of the 3rd cycle plants- which are now producing, but not tested enough to use for seed. A lot of them have outstanding nuts.
As you know, if you're harvesting your own, the smaller ones frequently have extremely thin shells; paper thin- or thinner. We do discard heavy shelled bushes in the breeding process.