Obxd sounds great, there are a ton of good patches and banks on KRV and the GUI is large enough to see and use. It's a very usable synth. I love the S&H. Thanks to the developer and all those that contributed patches.
I'm running Windows-7, 64-bit with REAPER 64-bit. I'll try it on the Mac soon.
This synthesizer is amazing; it's a very good, useful emulation of the OB8, from what I can tell, and it has the features I want an emulation of the Oberheim synths to have: clear, lush sounds, easy interface, unison, sample and hold.
The sound is incredible. It doesn't have a sub oscillator, but I haven't been able to tell if it really needs one; you can get the synth to grind low without much of a problem, especially with the unison mode.
There's not much that can be said about the user interface and features; it has a set of filters, the SEM's resonance and cutoff features that seem to be clear enough. (I don't have an actual SEM to compare against, nor am I really concerned about an exact match, personally; I just want the thing to sound good.)
All in all, a very worthwhile synthesizer; I use it with Cubase 7.6, 64-bit windows version, and it works very well for me.
There is no 'set' place to install the presets.... just install them in a folder of your choice (I put them in a folder called 'OBXD Patches' that gets backed up nightly so they don't get lost), then after loading an instance of OBXD in your DAW, go to the VST2 drop-down menu and choose "Load Bank..." or "Load Patch...". Navigate to the folder where you installed the patch banks or patches, choose the bank you want, and it will load. The next time you go to the "Load Bank..." menu, it will default to the last folder you opened. Remember to Unzip/extract all your banks.