For the sake of this blog, the comparison criteria is, Tone, Articulation and Build.
It's a scientific fact that metal and plastic resonate differently. This is most obvious on the Trumpet when looking at either extremes of volume, (ff - pp.) In this instance, the Sonata wins. Furthermore, it also offers superior depth and clarity of sound. Even so, that is not to say that the pTrumpet is a poorer option. As has been said in other blogs, between these two models, the overall tone is more affected be the ability of the player than the instruments themselves. If you're good enough you can make anything sound good and, lets face it, as a total beginner you've got the ability to make a Strad sound like a giant raspberry.
The pTrumpet valves are not always as responsive as its Sonata counterpart. This means the articulation is not as crisp. Yet again, for a total beginner or skilled player, this isn't too much of an issue. Also, while it appears that the Sonata wins this round it is worth being aware that the 'better' valves of a traditional Trumpet come with the cost of increased maintenance. For some this puts it firmly in second place.