Yup. FCP Legend had the RT Menu to the left of the timeline, Avid has it's yellow/green indicator beneath the timeline, X has Better Quality/Better Performance in the Viewer and PPro has Full, 1/2, 1/4, etc., settings under Viewer. I like my playback and shuttling fast and smooth even if that means the image during playback isn't tack sharp.
For example, my grandfather Mac Pro and OWC RAID can playback 4K R3D files okay, but if I FF/REV it turns into a slide show. Drop the playback down to 1/4 and the FF/REV is smooth again. Plus, at 1/4 and I can smoothly playback a green screen composite (both 4K R3D files) with a couple layers of color correction on top of it w/o rendering. I'd much rather drop the playback image quality a bit than deal with spotty performance or have to render a lot.