"Not only the routers CPU and memory are much more powerful but also links are much more reliable."

In addition to what Giuseppe has noted, how Cisco's OSPF paces LSAs, both the routine one and the changes, goes a long way to keep OSPF Dijkstra's algorithm calculations from causing issues. (Also later Cisco IOS images support an incremental Dijkstra's algorithm optional feature.)  (Reason I mention this, I've seen Brand X OSPF go into OSPF meltdown when Cisco does not.  I.e. don't assume you can place the same number of Brand X OSPF routers into the same area.)