The travel add-on is - in our opinion - a no brainer.
Worldwide travel insurance for up to 8 weeks at a time for 1.50 per month - and at the level of cover of full private health insurance.
Pretty much the only time when we don't recommend this is if you actively plan on not travelling outside of Germany for the next few years.
One trip per year and it's already worth it. We recommend in nearly all cases to get this one.