It's no problem to question the utility of any item to you. It sounds like you don't need anything besides what Savox offers, so there's no reason for you to jump to something more expensive.

When you say no better than a Savox, I assume you are talking the specs listed for torque and speed? While they are probably the only way to vaguely compare servos between brands, there are so many other specifications that aren't listed. Response time, tolerance/play in the gears, case material, accuracy, and software all matter. The Tekin servos use better position sensors, are element/slash proof, and will be upgrade-able with future software updates.

Given that Tekin used solid aluminum cases, the best Tekin/Savox comparison is the $140 Savox servo. For a $10 difference, the Savox still lacks the ability to be updated with software, spin a full 360 degrees, have its center point be programmed at will, and uses a lower tolerance position sensor.

The better comparison would be Futaba's S.Bus2 servo line. They are crazy programmable (you can even plug them straight into their latest radio to program them) and have features through the roof. And most of them are $200+.