Both are perfectly clear and correct, however I would consider the first one to be more modern and precise. *in vacuo* can also just mean simple distilled off using a shlenk line using house vac.
Typically I would remove 99% of the solvent with a rotovap, then hi-vac it on my line for some time between 20 minutes and a 24 hours depending on the material (polymers need more time).
If you did the same, then perhaps say "The majority of the solvent was removed by rotary evaporator, then the material was subjected to high-vacuum overnight on a shlenk line." Its precise, simple to understand, and fully detailed.