From AFP548’s Lion Server review:
Does this mean that OS X Lion Server is a slam dunk upgrade for everyone? No. In fact there are some folks that I don’t think I could even recommend to remain on the platform. If you are making a living doing web and mail hosting on Mac OS X Server then you are probably going to be better off moving to some other Unix or even Windows. The total gutting of web configuration when it comes to sites and virtual domains means you are going to be doing a lot of the same work in Apache2 conf files as you would be elsewhere. You can certainly get the job done on Lion Server and he price is right, but there just isn’t a compelling reason to do so.
For people that want to mange services for Mac, Windows, and iOS clients though Lion is fantastic. While the tools may have changed, the services that we’ve always had are all still here. Everything benefits from the upgrades of OS X Lion as well, with 64-bit now being the only way to go. The price is great and the install is simple.
Most impressively, you get a full blown MDM server for “free” with Lion Server. No developer account or third parties required. Just turn it on and go. This is bringing with it a huge shift in the way we think about client management on the Mac and I think the change will be for the better in the long run.