I have been a modeller ever since I was 9 - I'm 79 now...

I've been a member of the International Plastic Modellers Society since 1987, and I've made my fair share of modelling  blunders, and through bitter experience I have learnt never to apply acrylic over enamel. When aircraft modelling, I usually use either Hannants Xtracolor or Xtracrylix paint - both are gloss paints which removes the need for a pre-decal coat of gloss varnish: (for railway models I have always used Phoenix Precision Enamels - and their varnishes). 24 hours after applying  decals I then apply the varnish appropriate to the finish that I need, and I'll use the paint manufacturer's varnish. Of course, I always prime before painting, though I'll never use a rattle can, being an airbrush user for the past 45 years. I have nothing against rattle cans, except that I think that they're so darned inaccurate! By the way, I would always apply decals over a glossy, not satin, varnish. I make no distinction between modelling aircraft and modelling N-Gauge rolling stock when it comes to painting and decalling techniques. For decal setting/softening, I stick with MicroSet and MicroSol - been using them for over 50 years!

On the subject of Johnson's Klear, I haven't yet tried the "new" formula, as I laid in a goodly stock of the original formula when I heard that it was going to be replaced! However, I have heard good reports of the new version.