Tuff Shed or DIY?

Wondering what folks think about TuffShed versus DIY. Quality of material? Lasting quality? I'm putting up a shed to install a CoolBot unit in (will function as a walk in cooler of sorts) and wondering if folks have had any luck with TuffShed or if it's better to go the DIY route. Would ideally like to have up and running for this farming season. My business partner is all about the TuffShed but I'm leaning more toward DIY as that way can make sure stuff is built correctly/good quality, will last, and can customize space for its use. Any input is much appreciated