1. I like the look of the ELX better, but the SP888's baffle probably is better with regard to diffraction. Nonetheless, the ELX frequency response looks good.
2. I like that the SP 888 uses a concentric driver and the wide vertical listening window that provides. But, with the ELX, if you mostly will be in it's vertical listening window when listening, it may be a non-issue. The ELX's vertical listening window is very narrow, though (see the vertical contour plot on Ascend's webpage for the ELX).
3. The measurements of the ELX posted on Ascend's website look good, other than the vertical contour plot (see point #2 above). But, I question why they do not show the harmonic distortion, modulation distortion and compression measurements. Personally, I would want to see that data before making a decision.