300mm is quite a lot for general use tbh. I’ve got one on my Olympus so it’s equivalent to 600mm whereas it’d be more like what, 500mm for you. It’s approaching ok for wildlife if it’s big, or quite tame, but of limited use for creatures that aren’t afraid to be close to you.
Of much more use in those situations is my 40-150mm. It’s much much smaller and easier to handle, and whilst the apertures are the same it’s also faster in operation. This could be a feature of my particular lenses of course. It was also about half the price, and it’s sharper.
My 40-150 produces lovely background blurred shots of kids etc when running around in the garden or at a park or something – I’m typically far enough away so that they don’t notice I’m taking pictures of them, but not so far that they’ll be stolen by kidnappers.