I've been using Mac OS X Lion as my main development machine for the last month or two, and it is absolutely fantastic. I have had none of the issues he mention

I've been using Mac OS X Lion as my main development machine for the last month or two, and it is absolutely fantastic. I have had none of the issues he mentioned. Mail has been faster than ever, I don't have random windows closing (when in full screen) and when I drag and drop to Safari there is no issue what so ever. Do I like the new Mission Control UI over Spaces? No. That, and multi-monitor support being particularly broken makes me sad, but I have learned to live with it for now. I have no idea why this guy is seeing all of the issues he is seeing. I didn't do a clean install either, so far my files have come from: 10.2 -> 10.3 (PPC) -> 10.4 (Intel, used migration tool) -> 10.5 -> 10.6 -> 10.7. Without any major issues.