Although I haven't painted my Yamato Valkyries yet, I have done a few Transformers customs using Testor's Model Master. I have done other custom work such as McFarlane Sportspicks, and various resin and vinyl model kits, but for something that needs durability, I found that the Model Master paints faired very well.
I think Model Master paints will be good on the Valkyries as long as you do a thorough prep job by laying a good underlying primer. As with Transformer customs, there is still the likeliness for paint rubbing especially between tight joints. But with my experience with customs, enamels and lacquers are far more durable than acrylics. Aside from making sure you have a solid prep job, it is equally important to make sure your enamels have a full 100% cure dry time. I go as far as waiting 10 - 14 days for my enamels to cure on my Transformer customs. The biggest thing I notice with waiting this long is that it minimizes paint chipping or scratching. Keep in mind, there are many factors that need to be considered when waiting for enamels to cure: weather/temperature, humidity, etc.
I plan on doing a Minmay Guard custom Valkyrie and will definitely be using Model Master Paints. I will say that I don't use spray cans when I paint with Model Master. I strictly use an dual-action airbrush. So others will have varying experiences with this brand depending on medium.