As I said before, I thought it unlikely this lens would not have weather sealing, as it's clearly Canon's answer to Sony and Nikon's 600mm zooms, with an extra 200mm to give it the edge. It wouldn't make any sense to hamstring without weather sealing, to give Sony and Nikon an edge, when there's no need to give them any edge. Weather sealing is hardly high technology. I think most importantly, this looks like a serious stab at a good quality, wildlife and birding lens. Unless, there's something shockingly bad, I will be getting this lens. I finally got an R7 today (still been using my DSLRs). As long as the IQ is solid, I'll be getting this. However, in the meantime, I'll carry on with my 100-400mm mkII. I hope I don't misjudge this, and it's difficult to get for ages. I normally like to see tests and user experience first. 800mm without a tc, would be a massive advantage to me. One nice touch I can see, is some strap lugs on the lens, because I wouldn't like this hanging off my lens mount all day.