In the past we had IPSec tunnel between MT and ASA, no problems at all.
Not sure is it relevant for you, but I will share my case:
few days ago had issue with IPSec when client connects from NAT’ed ISP network (4G).
Tunnel initiated, but no traffic could pass the tunnel.
The solution was - turn on NAT-T on client side. Have no idea how to have NAT-T if client is Mikrotik.
I have created post, but later solved that case by my self 
http://forum.mikrotik.com/t/ipsec-problems-over-4g/137279/1