I prefer 'pasture boarding' to stable, or stall board; horses, when they have the choice would rather stand outside, even in the weirdest weather conditions...yes, they may go in and out of a shelter, but most will prefer being able to see and hear around themselves, to being inside, where things might be distorted. I don't think there is anything wrong with pasture board, as you know your horse will always be 'exercised' because he has room to kick up his heels when he wants to. Free choice hay, and water, are 'really' all a horse needs to maintain his body function well. But shelters, atleast a 3 sided one, are always good to have in the pen, so they don't have to stand out in every type of weather; if they desire, they can settle in the shelter to 'warm up' or dry off a bit. Mine all have access to run in, and yet, they are always out and about in cruddy weather...they could care less; it's me that gets weird about it sometimes!Lol!
My mare, who really hates wind, and would hide in her shelter all the time, now stands out in pretty much anything, now that she's realized I will blanket her accordingly. She is body, clipped though too, but she really seems to realize the blankets block the wind, which make her happier to be outside. Lol!
"The ideal horseman has the courage of a lion, the patience of a saint, and the hands of a woman..."