It features a fully variable ratio control from 2:1 to 20:1. Unlike the original 1176, the SST’76 features a traditional threshold control. This 500-series-style compressor uses a solid-state (SST) circuit model based on the 1176. The unison plugins are really great, some of the UAD reverbs are phenomenal (AKG BX20 comes to mind), UAD’s compressors are excellent, and their tape emulations are also fantastic. The SST’76 is available as part of McDSP’s 6030 Ultimate Compressor suite. Additional features the UAD version supports that the Waves version does not are the option to switch from black to brown knob for the low end. As a plugin it makes the Waves version look and feel like a kids toy. UAD plugins are renowned for their quality, as a matter of fact you can find reviews and testimonials in lots of places, where users do praise their quality. The UAD version captures everything the hardware has. My point: when recording, a quad-core should provide you with ample power, when mixing however (more plugins on more tracks) then yes, you’ll probably run out of DSP with a quad (or even hexacore) quite quickly And I’m talking 4 unison plugins, compressors and EQs on 4-6 tracks, reverb + delay in aux and occasionally a tape emulator in there somewhere as well. I have a Quad Core Apollo 8 and with effects lined up in the Console for incoming signals, I have yet to run out of processing power. It’s an approach that has served the 50-year-old Washington, D.C. Whether your Apollo runs out of DSP power depends on how many cores you have. Apollo & Unison PlugIns Jacquire King speaks the same way he produces and mixes records: he’s direct, to-the-point, and avoids unnecessary hype. UAD plugins sometimes do add latency, however, there’s absolutely no latency (< 1ms) when plugins are used in their Console app (the Apollo’s mixer) - that’s the whole point of UAD Apollos, you can perform/monitor/record with effects and the integrated DSP takes care of all processing Just to correct a few things stated about UAD gear in this thread: