I have a friend in the outskirts of Kansas City that put one up about 10 years ago and he has been happy with it.
I also asked one of the most trusted local contracters about them when he was putting a pitched roof on my commercial building last year, and he says he's out up a bunch of Perkas.
He told me the farmers around here love em because they go up quick and have a ton of room (clear span) for their equipment.
That was enough for me, so I am now in the process of saving up funds to put one of their buildings behind my house. I am going with the biggest my city will allow, a 36x48 and have around 20k saved up right now, but my yard has a good slope to it so I know my biggest expense is going to be the grading and concrete work.
I am going to get some bids soon on my concrete work so I can figure out how much more I need to save & budget for my build.
I'm in the TOpeka Kansas area.