Welcome to 'BULLSEYESHOOTERS' Dennis.
I have never used one of these sighting devices. However I know a
fellow club member who swears by the Merit. Said his scores had been
dropping for some time as he just could not see the target / sight
picture as well as in the past. He even got a new corrective
prescription that only helped a little. A rifle shooter mentioned the
Merit so he got one from Brownell's ... I think.
A quick meta search turned up these links:
http://www.meritcorporation.com/ ...or...
http://www.meritcorporation.com/products.html
http://www.gunblast.com/MeritOptical.htm
http://www.findarticles.com/p/articles/mi_m0BTT/is_158_26/ai_86704810
http://forums.sixgunner.com/m.aspx?m=23645&mpage=1&key=
Good luck,
Pat Cimo
SR25MK4