I've been developing in Filemaker Pro 6 for years now -- the agency I work for didn't spring for the upgrade to 7 right away, and we have just been sailing along with the legacy system the entire time. Database development isn't my primary job duty, but I'm very comfortable creating new applications and making changes to our existing one.
However, we can't put off upgrading any longer due to newer operating systems, so I'm planning on an upgrade within the next six months. We have roughly 30 FMP clients. Files are on a FMS5.5 server.
I have spent a little time with FMP12, and from what I can tell, the overall concept is the same as FMP6. The interface is slightly different of course, and we're talking about tables now instead of files, but it's not nearly as foreign as I expected it to be after six versions. Are there any major (i.e., architectural or conceptual) changes that I should watch out for before digging in?