Fully agree with you John about the quality of the Bushnell glass. I have one of the Bushnell "Triple tested" Featherlight models made by FPO around same time as the Rangemasters and it is simply superb. Perfect collimation and great contrast and sharpness - esp. without all the modern bells and whistles. Mine is an IF model and the optics are crisp and sharp with even good edge performance. There is not a spec of internal "funk" with mine, and of course the IF part helps with that. Mine have the same size and prism housing as these Bushnell 7x35 Rangemasters on Fan Tao's site (Except mine has the FPO marking and Japan under it on the hinge cover plate on the objective end).:
http://web.archive.org/web/20070206190840/http://fantao.home.att.net/rangem.htm
And I also have a 6x30 IF Bushnell Featherlight that is simply fantastic- I cannot believe how good the optics are. I got it a few years in a local thrift shop and did not know much about it when I bought it- other than saying to myself when I looked at them outside the store "Wow- these are quite good". So I bought them and took them home. Did some research on them and saw the 10x50 ones on Fan Tao's website, and realized that they were a very well made binocular from the past. My Sample of 6x30 is quite beat up externally- but the inside baffling and the glass on the inside is pristine. I really think that the old IF bino's are so well sealed- that they do not allow the gunk inside that the center focus ones sometimes have. Of course this makes sense. They really made those IF bino's to withstand a lot. And the collimation I believe stays a lot better.
From strictly a detail resolution standpoint it actually is as good or better than my Leupold Yosemite 6x30. It is not quite as good as my Swift 6x30 Seahawk (that is better optically than the 6x30 Yosemite) but it (the 6x30 Featherlight) is pretty darn good.
It is identical to this 10x50 Featherlight on Fan Tao's site - My 6x30 is a USOL version that is just like the 10x50 on bottom of page:
http://web.archive.org/web/20070206190224/http://fantao.home.att.net/fpo10x50.htm
I also agree with you about lower power bino's- I love 6x and 7x galss.