I’m using RouterOS for IPsec, in my topology are included cisco routers and Mikrotik Routers, I do not have any problem it is reliable and works great, no problem connecting with cisco.
One of my tests has shown that with a PC celeron 2.53 GHz, 256 MB RAM, I had a maximum 3des throughput of 45 Mbit/s full duplex, and CPU at 90 to 100 %, but to keep CPU at 30% the maximum throughput was 20 Mbit/s full duplex 3des encryption.