I’m a DAWaholic and own and have used both … along with Pro Tools, Ableton and Logic.
The two most opened are Pro Tools and Cubase. For music creation it’s Cubase all the way with its deep midi and project arrangement tools. To be fair, I know it better than Studio One and since it always does everything I want, I haven’t dug into Studio One to the degree it probably deserves. As an aside, some of Cubase’s original developers are now the development team for Studio One.
But for straight recording and mixing I prefer Pro Tools for the simple fact that once you learn the key command short cuts you can do 98% of what you need without going to any sub-windows. Pro Tools Native now has VCAs and all the bussing you could wish for. Clip gain is an incredible tool for gain-staging your tracks and simple to use. Speed and depth of audio editing is why Pro Tools retains its place in studios despite all the dissing about lagging implementation of ‘innovative’ features introduced by other DAWs.