I just (within the last month and a half) earned my ACTC 10.6 Certification, which certifies a solid knowledge base of Snow Leopard Client and an introductory knowledge base of Snow Leopard Server. Admittedly, reading "Mac OS X Server Essentials 10.6" and training therein was my first ever exposure to any version of Mac OS X Server, let alone Snow Leopard Server. I hold the ACSP 10.6 and 10.7 certs and know a lot about the client OS systems for Snow Leopard and Lion as well, but I know nothing about Lion Server. This brings me to my question: I haven't yet cracked open my "OS X Lion Server Essentials" book to prepare for my ACTC 10.7 Certification, though I am planning on doing so in the not-too-distant future. But in the meantime, I've played around with Lion Server for about an hour total and aside from the "Server" app both replacing the "Server Preferences" app and acting as the delivery mechanism for the package that converts/differentiates Lion client from Lion Server, and some new iOS management features, I can't tell the difference once the 10.7 Server Admin tools are installed. I've read a number of negative reviews on the Mac App Store for Lion Server, but I can't tell if those are from people who don't know to download the 10.7 Server Admin tools separately and are complaining about problems that there are already solutions for or if there are actually problems with Lion Server that make it a step down from Snow Leopard Server. So as a Mac sys-admin newbie, given that I have a while before I can crack open the "OS X Lion Server Essentials" book and I want to have somewhat of a preview going into it, what are the real changes between Snow Leopard Server and Lion Server? What are the major complaints? And in the opinion of someone who knows, are these complaints valid? If someone more experienced in these matters could share, that'd be most appreciated. Thanks.