We have about 1600 users in our environment, across more than a dozen divisions or departments.
Layout templates in a complex environment are one concern -- custom forms and fields are bigger concerns.
Within the IT division, we've been developing a couple of standard templates for users based on their needs: Individual Contributors (analysts, system analysts, engineers, etc), project managers, and department leaders. We also have a couple of "special purpose" templates currently for one of our departments, adding a layer of complexity. For that department, it is simply an added tab in the reporting area -- all else SHOULD be the same.
For other departments, we either have not been using the layout templates or have developed specific need templates. Since most of these are pretty isolated in their needs, it is generally low support.
What we're finding now though is that as we mature, we are coming together more, and the old days of individual divisions having their own custom data elements has become more of a hassle to maintain and more confusion to the users. As such, we're now in a concerted effort to wind back some of the data fields and standardize. Don't make the same mistake we did -- standardize early. Multiple custom forms help enable that - a standard form for all required common elements and additional forms for department specific items.