The latter. I think it's a 1% business case, basically. I mean, if we can get 80% benefit without excessive cost, then it's obviously a good idea. (And I do use Ansible/Docker and the like, but it's not entirely without friction... which is where the cost/benefit analysis comes in.)

EDIT: Obviously, if you really need clustering, then you need it, but IME people tend to overestimate their needs drastically. Everybody wants to be Big Data, but almost nobody actually is.