pawpatrol, the reason the German knight has seen so much time on the boards of the top tournaments is that the set was DGT default for the electronic boards. I don't think anyone chose the pieces based on looks.
In recent years some tournaments, like the Sinquefield Cup (HOS Imperial Collector), WYCC 2012 (Best Chessmen Ever) and even the world championships (custom set), have introduced other DGT compatible sets. Presumably because they felt that the normal DGT offerings didn't cut it.
Some tournament organizers just don't seem to care what type of chessmen are used. If I remember correctly, some of the US championships, back before Bobby Fischer became the world champion, were played with plastic pieces.
I'll have to check out the international series. That HOS Gambit set looks great. I do love the HOS sets - they're all so well done.
That set in particular(the HOS Gambit), is designed to be played with(toss em in a bag and go). The rims of the bases are thicker and less likely to crack. They'll make any chess set look like a little brother, especially that horribly cheap looking set above, that knight is about as cheap looking as it gets.
There isnt a set in the world that will compete with what you get, not for 100$.
That "horribly cheap" looking set above is on par with all of the HOS sets I've owned and used in terms of quality. As I suspect, if your opinion is just based on the knight's design, that design is called the "german knight" and is actually quite a popular design. It's a simple design, not a cheap design. Again, the quality of this set is on par with the HOS sets.
Some examples of this design being used in top level tournaments: