Morton has done 3 projects for me (on my 1 acre). Their buildings are straight, square and pretty solid. You will probably find their quote on the high side on a straight per square foot basis. I think they are worth the difference. My oldest Morton building is about 20 years old and is holding up better than my house is. It is now overdue for it's first paint job and the original gutters are shot. Otherwise it is doing fine.
Here it is:
After they finish a project, they get a little forgetful about coming back to fix construction errors or water leaks. You have to keep after them.
By the way, they pay a small referral fee to their prior customers when one of the referals makes a purchase. See if you can find a customer near you that will show you their building, then let them send your contact information to the company. If you can't find a customer in your area, I'll be happy to refer them to you.