Is there a way to add something like speedtest-cli to routerOS?

Would be great to see what the router could see from a speedtest server.

speedtest running on the tested gear is going to be inaccurate as CPU is used to do more things with packets.

If you want to see whats in between do a sniff and run speedtest from behind it.

The only use case for speedtest/bandwidth test from the router is when you are testing link speeds without maxing out router CPU.

Check out this link http://forum.mikrotik.com/viewtopic.php?p=527754

Tom has very kindly setup a remote btest server that you can test with. Please read the forum link above and do not abuse it.