It's 2% of a semitone off by my understanding. I thought I had pretty good ears but I really doubt I could pick that. Open strings do often stick out in general on string instruments though, for a combination of reasons, lack of vibrato and ability to micro-adjust tuning presumably being the main ones (but even the tone is different, I assume based on the difference between having one end fixed by a soft fleshy substance vs the wooden nut).