I've never been real happy with the stock sights. Though adequate, I figure they were made for a longer sight radius. As it is on the shorter Deerstalker, the front bead is a just a tad too big for the rear notch. One could certainly open up the rear notch without much difficulty.
Then there's the issue of adjustability. As it is you have to drift the rear for windeage, and for elevation you have to loosten two screws, fumble the rear leaf up or down, and tighten the screws without letting the leaf shift in the process. It works, but it's a pain. I have mine set up for PRB now, so if I want to use conicals I have to it all over again. I'm resisting that.
In theory, there's nothig wrong with an aperature sight for hunting. American Military rifles have had aperatuire sights for decades running. You just want an aperature size that works for you. I'll tell you without hesitation that I'd much rather use the AR-15A2 aperature sights, for example, than the ones on my Deerstalker any time of day-- I consider them vastly superior.
Be aware that some states restrict the type of sights you can use for ML seasons.
Any good adjustable sight would be an improvement, as it would let you change loads easily.