Well, I ain't no expert, but....
I prefer to spray. Fill all those pesky little holes and cracks, give the hull a good rub down with something like 240 grade paper, then a high build primer. This will probably reveal more pesky little holes and cracks, so fill those. Then several top coats should give a good finish. And no brush to clean afterwards!
Of course, spraying does need more care in where and when you do it. You can brush paint inside the house if you are very nice to SWMBO, but even the most ardent modeller would draw the line at spraying in the house (I think
!) And you can certainly get as good a finish with a brush if you are careful, it just might take a little longer.
So ultimately it's up to you. Where do you do your modelling? That will probably determine how you do your painting.
Happy painting!
Greg