The keycube is a tangible cubic device including a text entry interface for different apparatuses such as augmented, mixed or virtual reality headsets, as well as smart TVs, desktop computers, laptops, tablets. The keycube comprises 80 keys equally disposed on 5 faces. In this paper we investigate keycube text entry performances and the potential typing skill transfer from traditional keyboard. Using prototype implementations, we conducted a user study comparing different cubic layouts and included a baseline from traditional keyboards. Experiments show that users are able to attain about 19 words per minute within one hundred minutes of practice with a QWERTY-based cubic layout, more than twice the speed of an unknown-based cubic layout with similar error rate, and about 30% of their speed with a traditional keyboard.