*Edit* Did not see that the question was pointed towards MAC. So the answer applies to Windows users.
Simple answer is, yes and yes. It works like Plex, and are capable of so much more. I would recommend trying out the latest build and use the trial period to test out new things. And to use this forum actively if you encounter problems or have questions. The folks on this forum are generally very helpful and friendly.
At first test of JRiver Media Center, it might strike you that it looks a bit "simpler" than for example Plex or XBMC. But this is mostly because JRiver does not have that many skins as other competitors. If you have the time to set it up right, it can do about the same things as other MC's, and a lot more in addition. It can also be transformed to look pretty much like what you've been used to.
JRiver MC sync does not work with the newer iOS devices, but there are popular plugins and applications that can do the sync pretty much automatic from MC, via iTunes in the background and to your device. The beauty of MC is that it can be used the way you want. You can use it as a standard desktop application on your laptop at work and listen to your music that are at home or you can use it locally with a remote in a 10 foot interface on your big screen TV. You can use a Windows laptop/pad as a touch screen remote, you can use Android devices as playback and controlling devices of all other MC installations, you can use your iPad as a remote control and playback device (there are several good apps on the market), you can connect all clients to a central server or an "always on" HTPC to sync all changes in your media network and share the media with your whole family, friends, or just between your own devices. All are based on a superior database that handles all media in your own way. You can add tags, create views based on those tags and sort in any way you like and display the media in almost unlimited ways.
If you only look for bling then MC might not be your cup of tea, but in all other cases MC should be the superior MC application out there.