Personio API being slow

I’m trying to sync Personio employee data with a third party tool. I’m using the code example provided in api docs:

const sdk = require('api')('@personio/v1.0#1fzp...');

sdk.auth('eyJ0eX…');
sdk.getCompanyEmployees({limit: '100', offset: '0'})

Doing auth-get on a loop, until I fetch all the data. 

When using page size of a 100, each request to getCompanyEmployees takes 20-30 seconds. 
If I reduce limit to 10, request times range from 3 to 13 seconds. Leaning towards the lower end. 

Is this expected? Are there any best practices to follow, to speedup getting the data?