It was indeed close. You are comparing apples to oranges.I think k Boxem posted a quick measurement of their version in another thread, but it wasn't close to this.
115 dB is obtained by summing the THD measured on one side and the noise measured with inputs shorted on the other side.
The March equivalent to what I measured is a bit below 112 dB while I measured around 110 dB with a different generator.
I would also like to know at which gain these measurements are done, since it can make a huge difference.