Interesting...certainly the paints and brushes are going to have a huge impact on your product, regarless of your technique. I agree with Jeff, if you are going to use enamels, use the Humbrol. If I am going to use enamels, I will always elect to use Humbrol first as it is the most "workable" and easiest to control. Using acrylics (as you have), then giving them a gloss sealant is fine and has a similar effect. I have been through many stages of painting techniques and materials: I started with enamels, then acrylics, then a combination of both (so I could have some glossy articles, like visors and other leather equipment) and because those parts of the figure that get a lot of wear (like the head) don't respond well to handling if painted with acrylics without a sealant. Then I discovered glossy acrylic!!! Man, I love this stuff. It handles like flat acrylic but has a great sheen, and...if you water it down, you can control how glossy it is (let's say you just want a sweaty horse...semi gloss). Of course, the figure will still need to be sealed. I use Vallejo paints for certain colors that I find difficulty mixing consistently (military green, for instance), but for the most part, I don't see the value in what those tiny bottles cost. I pay between 58 cents and $1.50 on 2 oz/59ml bottles from Michael's or AC Moore. Great bargain...great paints, and usually easier to work than Vallejo (never randomly watery as Vallejo can be if you haven't shaken it for 20 mins).
Brushes go without saying. The better the brush, the better your painting will be. All my brushes are tiny. I rarely find a use for anything over a 1. The most useful being 15/0. If you take care of your brushes, keep them clean, they will last a very long time.
I like Tradition figures the castings are crisp and full of detail.