For an ED50, there would appear to be 3 different 27x eyepieces.
1) 27x MC (tiny, weighs 35g)
2) 27x MC Wide (far less tiny, costs much more, weight 165g)
3) 27x DS (for digiscoping, 180g)
#1 tiny, cheapest, narrow field of view, weighs nothing - what is the optical quality versus the others...