One other thing no one has mentioned is long term value. Most pole barns, at least in this area, aren't considered to be worth that much or add much to the value of a property, unless they are exceptionally nice, with finished interiors, etc. I suppose that is because most that build them are saving money, so they usually aren't insulated and are just basic buildings.
I built a 40x60 all steel 4 years ago, and am very happy with it, except for the cost. I have about $53k in it, including fully wired with lots of lights, and a 20x20 area in the one corner that is framed in with storage above. Also a 65'x20' concrete apron 6" thick in front.
I have 14' sidewalls, so it looks better in relation to my house, and the open span inside is very, very nice. The storage area would be difficult to access in a pole barn with trusses, as it would only be about 4' high overall, except between the trusses. A good way to bang your head!
I had an estimate for a pole barn that was $32k, but this didn't include insulation or any electrical, and only a 4" slab (mines 6"). I thought I could build it for around $35k, but...... It's strange how things keep adding up!
I also have radiant floor heating in it, so that was another $2,500 just for the tubing and insulation. Another thing about pole barns is that they are very hard to insulate properly, unless you line them on the inside. How do you hold insulation on the walls when the poles are 8' apart? It isn't easy, while steel buildings will almost always be insulated as they are built.
And if you don't like the idea of compressing the insulation on the roof at the purlins with the screws, use the a standing seam roof. These are great, with no external screws and no compression of the insulation, but they add quite a bit to the cost, around $2 - $3 per sq ft if I recall correctly. It isn't worth it unless you plan to work in it and heat or cool it on a daily basis, such as in a commercial machine shop. But they are the ultimate in longterm, durable roofs.
Would I do it again? It depends! For a shop that you want to work in and store things in, yes, probably. But for animals or strictly storage, no, I would build a pole barn. Much cheaper and quicker, especially if you don't pour a slab.
Keep in mind that most metal used on pole barns in around 28 or 29 gauge, while on a metal building it is usually 24 gauge on the roof and either 24 or 26 on the sidewalls. This is how they are able to span larger areas without needing as much support, as most metal buildings put the purlins 5' apart on the roof, and the girts up to 8' apart on the sidewalls. This translates into the metal on pole barns being a lot lighter and more prone to dents and dings, and getting banged up in general. And it will rust through sooner in an acid rich environment such as with animals.
But ultimately it's your choice, and you get what you pay for.
