It's really disappointing that 10oz will have the same diameter as 5oz version. Not a big fan of "thick" coins. And missed opportunity in my view.
Kilo silver is limited to 350, but price is crazy high. For this price you can get 2 other kilo coins. Libertad kilo is minted in a little bit higher numbers (depends on the year), but it has (at least for me) much better and more interesting design, even though Jody Clark is for sure talented.
I also wonder how it will be with milk spotting. I like Britannia 2014 5oz proof a lot, but it's very hard to find one without milkspots. I think mine developed tiny ones, but it's still very annoying and disappointing.
As always it seems with Royal Milking one needs to be careful with mintage numbers as it seems there will be some sets released or something.
If I have spare money I would maybe buy 10oz, but considering the price and milkspots I'm not so sure.