A given commercial product MIGHT be the right choice for some given modeling task. I happen to believe that solartex antique is a pretty good match for an EIII. On the other hand, it doesn't look right for an Albatros CI, or IMHO any of the British aircraft. The problem with the linen is that it really is too opaque (and very yellow). Actually, it's completely opaque, which is why modelers use it...it hides non-scale structure.

Another key part of my modeling philosophy is that commercial products are almost always just a starting point. On my Snipe I used Jerry Nelson's PC10, but only after I tweaked the color myself. Similarly, when I used solartex antique on my EIII, I gave it a think latex wash that "personalized" the color. One reason why I believe that we so many fine WWI models coming out of the UK (and Europe) is that I think there are more "old school" modelers over there, builders who don't expect to be able to "buy a scale solution."