Actually if I am not mistaken the MC-E has been continually and quietly updating the bin codes so it really isn't far behind quite yet. I wouldn't quite go so far as to call it a legacy product quite yet.
As far as other options, I did a review here on CPF and on MY SITE of a XR-E R2 Throw monster drop-in.
Did Cree move to the EZ900 die in the mc-e?
That would extend the useful life of the white mc-e until the xm-l arrives.
The xm-l package is 5 x 5mm, where the mc-e 7.1 x 9mm. SST-50 7.3 x 9mm, SST-90 10 x 11mm
I'd like to see what kind of beam 4 xp-g [3.45 x 3.45] in close formation would produce.