Modelsim vs. Quartus II Simulator

The quartus simulator is quick to set up and useful for simulating design blocks that are fairly simple, have smallish number of inputs (and these inputs are basic to create, ie. not complicated 32bit buses) and the simulation time is short.

If this is not the case then you could spend a long time either setting up the simulation or actually doing the simulation. This is where Modelsim is great, its much faster at doing simulations of large designs (and/or long simulations) and you can incorporate testbenching for complicated input sets.