Well, to be fair, if your models painted with Testors paints are shiny, it's probably because you didn't read the label and used a gloss color instead of a matte color.
Enamel paints were the standard for many years (until the early/mid 1980s) and many people still use them (or other enamels, such as Humbrol) and produce fine work- primarily, larger scale historical figure painters. In fact, early on, one of the 'Eavy Metal painters (Fraser Gray) did all of his models with enamels. (I'm pretty sure GW would never allow that these days, and if they did, they'd certainly never let him say so on the pages of White Dwarf.) There's a Dust Tactics player on the FFG forums right now who lives in Argentina and can only get Humbrol enamels locally, and he's doing some outstanding work with them.
That being said, though, enamels require a very different painting technique than acrylics. They require solvent based thinners (such as mineral spirits or turpentine) for thinning and clean-up. Also, 99% of the information you'll find in the web concerning painting miniatures will only apply to acrylic techniques. One of the trickiest things with enamels is that unless they've dried for many days, solvents in fresh paint can re-wet previously applied paint, making layering very difficult. You can get some very nice blends, though, with practice, by applying two colors next to each other, and using a brush dipped in solvent to re-dissolve the area where the two colors meet and blend them together. But in the end, you are probably better off sticking to acrylics.