Overall, a very good rendition of LEBL, and certainly an big improvement over the existing versions by LVFR and JustSim.
I don't own the Sim-Wings version but I've made some meticulous comparisons (using the online resources available to me) and, perhaps surprisingly, the MK version matches and even exceeds it in a number of key areas. MK's terminal textures look better and the whole area to the east of the old terminal has been done in more detail. The only area that seems better in the SW version is the cargo centre. SW also arguably has better terminal interiors, and I imagine they'll have used custom Spanish airfield lighting/markings as they typically do.
SW added the port area in an update — presumably because MK's included it by default — however it looks rushed, with MK's having better detail (MK's port looks great at night).
I'd ideally like to give 4.5 stars due to the lack of custom Spanish airfield signage/lighting but I don't think the omission warrants dropping it to 4.