Use streams endpoint for live streams, until Helix has offline data endpoint.
It’s not slow. It’s caching.
Any game/title change will take 3/5 minutes to show in the API (both Kraken/helix have this). So it’s not slow, it’s caching. And you will sometimes hit a server in the pool thats not got the update yet.
http://shouldiblamecaching.com/
You may want to look at Webhooks instead