Well, I don't know about the Vanilla since I haven't ridden one. But I think that one of the reason where the Fox Talas (or RS Pike or Revelation) fits right on the Moto Lite is that you can adjust rear travel from 4" to 5". Well, at least, that was my reasoning to get the Talas R (I didn't had the $$$ for the RLC).
But I don't think it's a must to have variable travel, it just depend on your riding style, I think.
But I don't think it's a must to have variable travel, it just depend on your riding style, I think.