Vagrant is the best for testing / try out.
My first impression of the FreeNAS forum is that there are a lot of old white guys here who like to deal with outdated technologies.
Maybe I am wrong, but the forum gives such an impression.
[moderator note] Any further racist, sexist comments will not be tolerated. You have been warned.
As for "outdated technologies":
Perhaps you don't understand what FreeNAS is. FreeNAS isn't some virtual machine you run on your Amazon or OVH cloud host. FreeNAS is software that is designed to run on a physical machine, to manage a large number of physical hard drives, to provide storage to a local network. This is almost diametrically opposed to what Vagrant and similar technologies are fundamentally all about.
There is a certain class of software developer that finds it convenient to pretend that the cloud is just some magic thing that appears on demand to do their bidding, when in fact it is actually hosted on physical machines running infrastructure software like ESXi, Xen, KVM, and infrastructure storage systems like FreeNAS, VSAN, Nexenta, Joyent, etc. These systems are not really designed to run in a virtual machine, even if some of them can be for evaluation purposes. Your wonderful virtual Vagrant-filled world wouldn't be possible without those of us who build and maintain the very real infrastructure upon which it rests. I don't care if you feel that bare metal servers are "outdated technologies", they underpin literally everything you do, and without them, your cloud wouldn't exist.
So, also, don't be insulting.