If you were to create an application that relies heavily on a time series database, what would you recommend?

I'm writing an application of this sorts, and my requirements won't be too bad (about 1000-4000 metrics on a per second basis). I will also rely heavily on predefined queries (rollups to 10s, 1m, 10m, 1h, etc.).

I'm hesitant to use OpenTSDB because the community "buy-in" seems to be going down.

EDIT: I can't lose data to downsampling. I will need to store this for both troubleshooting and regulatory purposes.