Is listunspent scalable and efficient?

Is the listunspent bitcoind api command efficient and scalable? Say I had 5000 daily transactions on my bitcoind and I pinged bitcoind with listunspent every minute to keep my db updated, for example.

Any good alternatives if so?

I call listunspent 86,400 times a day per client, and I have about 10 clients pointing to the same bitcoin daemon, so that makes it a total of say close to a million calls per day, and it works absolutely fine without a need to restart for weeks.