We live on 3 acres and have an additional 12 acres that is recreational and eventually a cabin. We bought a JD Garden tractor from previous owner of the house. When we bought the additional property, mowed it a couple of times with the garden tractor while deciding on something bigger. We ended up with a Kubota B2920. Tried it, a BX and a B7800. Bought it with a loader and belly mower and then also bought the Rough cut brush hog mower.
Only negative I have for B series Kubota is when using the rough cut mower, the front of the mower will not stay set at a specific height. It will gradually drop as you mow, so you have to look back and bump up the height. This is because the 3pt hydrolic system uses a 1/4 valve system instead of a position control system. But once we had mowed the property several times and I got the rocks picked up, I mow it with the Belly mower. It can be set to a specific height and will stay there. So it is no more of a big deal than running your lawn tractor. If your pasture is in pretty good shape, and no brush to get under control and not a bunch of rocks, you might find a tractor with a belly mower or a rear finish mower (rfm) works better for you. Even if you needed someone else to brush cut it the 1st time. The rough cut mower will throw anything it picks up (sticks, rocks, horse apples) with a lot of force so make sure horses and people are not around.
The belly mower on ours is the drive over style like JD and it takes about 5 minutes or so to hook it up or take it off (hugely easier than the garden tractor). Biggest advantage is you can get around obstacles easier with the belly mower. The RFM is cheaper than a belly mower, not specific to the tractor make, so more choices and hooks to the tractor easier than a belly mower, but not as easy to get around obstacles.
My wife likes driving our tractor. My only complaint about that is it leaves me doing the real work. As has been stated try out different sizes, brands and dealerships, and it will become more clear.