IMR makes it in Canada, it's just a hair to fast or too slow to sell as regular 4350, so they surplus it, that's why you have to work up a load if you are a max load kind of guy.
I just got a jug but haven't got into it yet, with the D4064 I've used it a lot, it is a very good powder, single digit ES in 308, great groups in 6.5CM and 223. It's not going to be far off the regular IMR load data at all, powder company's are very picky about burn rate, has to be very consistent to sell commercially. With the 4064 version it's a 1/2 grain faster then Varget according to my chrony, so I just drop my Varget loads by 1/2 grain and get same velocity and slightly better ES.
I've used a bit of the D4895 and the lot I got was slow, so in that one I had to bump it up over IMR data.