I have now had a try of the Vortex 50, Nikon 50 and today was kindly allowed to have a look through (and a good go on) an Opticron MM3.
The vortex was beautiful, crisp, clear, but failed on the eyepiece and eye cup (rubber fold down). I didn't like that at all. Secondly it was a fixed offering, also I didn't like it.
Nikon 50, 27X fixed wide was AMAZING - clear, crisp, perfect raptor watching scope. However, the zoom eye relief was far far too restrictive and then there was the case of availability and increasing costs.
So this morning I met a lady from the RSPB (on holiday up here in Scotland) had the MM3 with a 24x wide field watching the geese at Findhorn bay. Let me be blunt here - the eyecup is smooth, the focus is so exact it 'drops in' and gets to sharp no hassles what so ever. The coarse is smooth, the fine focus is smooth, and is equal to my eye to the Nikon in every respect but focuses easier.
All in all, I absolutely want one. As for portability, my Hawke Frontier ED binoculars are heavier. I am in love. Seriously, I so badly want one now lol.