Also, because FreeBSD uses Kyua, its test infrastructure can be composed of test programs of various kinds (including legacy test programs and TAP-compliant test programs) and not only ATF-based test programs. This is something that NetBSD cannot do yet.
Note that NetBSD does have Kyua in the base system (optionally), but moving the continuous testing systems over from the ATF tools is a stuck project. The reason is that Kyua needs some more work to make that a reasonable migration for the people that run such machines. In particular, the generation of reports needs much improvement as well as the collection of results from various hosts. See http://wiki.netbsd.org/kyua/import/ for some details.
However, because FreeBSD needn't be tied to the deprecated tools, and because I am the one setting things up from scratch, I am using this project as a playground for the new framework. Doing this deployment in a major project quickly surfaces all kind of big issues that need addressing -- and is certainly a boost in willpower to fix them :-)
(Yes: an eventual goal is to also move NetBSD over to Kyua but that will have to wait until Kyua proves itself "good enough" on FreeBSD's land. Homogenizing the two systems will have the nice result of simplifying the sharing of tests!)