Which one of the above is the best buy for actual contrast and view.?
I’m aware the SSW has received a lot of negative reviews overall especially in relation to associated seap.
Is this a factor mainly in the longer focal length eyepieces though?, not sure if the issue is a factor in the 5mm ssw.
Any users of the 5mm ssw that are very happy with their purchase?
The ES 5.5mm is a likely better fit between my Televue Delite 7mm and Wo uwan 4mm.
In relation to price can buy the Vixen new for £100 stg less than Es 5.5.
Which of these should I purchase?
Were you also asking for a ranking on the list that Mike (Sarkikos brought up?).
I don't have the XO, but have/had the other three.
As far as contrast goes, I would rank them:
Nagler zoom first; and tie for the 5XW and 4.7 Ethos.
Based on all of the gushing I hear, my bet is that the 5XO is very, very slightly better than the rest on the planets on the best possible nights (If you can stand the horribly small field and minuscule eye relief).
FWIW, if the 7 SSW is representative on contrast, I see it as slightly ahead of the 7XW (which is widely regarded as either the best of the series or tied with the 10). If so, then the 5 SSW is probably a tiny bit ahead of the 5XW and 4.7 Ethos on contrast.
But again, the differences are tiny. If you have a non-driven mount, going for wider field/comfort preferences is generally a better strategy IMO.