Some things you should know. First the software is terrible. It looks and behaves like it was written for Windows 3.1 (client/server) and although the version numbers change there doesnt seem to be much of a difference. If you mention this to Deltek they will tell you they are moving to web. What they usually wont tell you (unless you ask) is that you can only do about 60% or maybe 70% of the things that you can do in client/server in web. Web and client server also use different security structures and databases so you have to synchronize it and all this is just the start of what I see as a big mess.
Get ready because everything you take for granted in an accounting system, all those things that normally come with a system like default reports, security, a display bigger than 640x480 dont come with this software. It also seems like the Deltek consultants supplied by Deltek are usually terrible. If you do go into this I would find some good outside consultants, if you dont have to go with them. Run!