I have some very limited experience with them on deer and the best I can say is that they make the deer dead as expected.
This 123 grain Sako load seems to be very popular with a number of highland stalkers and it seems to work well for them. As these are people who shoot a lot of deer I would say their experience is worth a lot more than mine and that it would indicate that the load works well.
I managed to get a very old box of the Sako to zero my rifle with and it behaved very strangely in that the first 17 rounds formed two distinct groups on the target. I might be given to think that there was a problem with the barrel heating up or something but can only say that no other ammo has ever done this in my rifle. It looked to me like it was shooting to two different POI. However, the final 3 rounds from the box shot a good group right on the money. Because of the strange behaviour I fired all 20 rounds from the box but must highlight that it was very, very, old ammo and was the only box I could get in this part of the world.
So, with some slight reservations, but based mostly on the fact that a lot of very experienced people seem to favour it I would be confident of its performance on deer if it shoots well in your rifle. If it were not for availability problems I would use it more myself.