I grew them years ago. I planted maybe 16 plants each year and the best year I ended up with 12 healthy pumpkins. I had a variety that grows smaller pumpkins though, I've never tried growing one of the more "normal" sized pumpkins.
You do pretty much need a dedicated space for them. Pumpkin plants are vines, and they absolutely take off in late summer and require a decent amount of space. I had mine in an area that was probably around 10' x 10' and they filled that space up and I occasionally had to adjust them because they'd try to wander out of that space.
In my experience they weren't difficult to grow, you just need to make sure they get enough water. My pumpkins were far from a water source so eventually I stopped growing them as I got tired of pulling 70+ feet of hose out to them all the time. Otherwise the only other issue I had were squash bugs, but I'd just scrape the egg masses off and ignore the adults. I don't think squash bugs are as much of an issue on large plants but can kill young plants.