SPAIN
The Spain is one of the larger empires in Austerlitz with large colonial holdings.  Its army is of poor quality but expensive elite cavalry is available for Simulated Battles.  Its navy is second only to Great Britain.  If allowed to develop the colonies, the Spanish economy, and thus army, can be formidable.  The longer Spain has peace in Europe, the better. (sample GUI empire file)
Economy
In Europe Spain begins with a large population, a fair number of resource co-ordinates (though, only a single ore mine), and plenty of terrain for quarries and lumbercamps.  Madrid is Spain's lone European Trade City and none of its barracks are in a good location for baggage trains.  Spain's trade is done mainly through its merchant fleet, and it has excellent access to the high seas.  Spain's colonial empire is impressive and highlighted by three Trade Cities in the Caribbean: Santiago de Cuba, Vera Cruz and Cartegena.  It begins with several mineral, foodstuff, and vineyard resources and has immediate access to much more.  Its position in the Caribbean is dominant.  Spain also begins with a mine in India and troops there for rapid expansion.  Not only is Spain in an excellent position to trade in the colonies, but also can produce large amounts of goods for sale in colonial Trade Cities or shipment for consumption in Europe.

The Army
In Europe Spain starts with only 8 brigades of lower quality troops, which are generally inferior to the other European armies.  The line infantry and light artillery are sub-par (EF = 6) and Spanish Grenadiers are weaker than normal (HC = 5).  The cavalry is better, in particular elite Garde de Corps cavalry (EF = 10), but Spain does not start the game with these elite units.  Spain starts strong in the colonies, with 7 brigades and a commander in the Caribbean and 3 brigades in India.

The Navy
Spain has the 2nd largest navy in the game.  It consists of 28 ships, 1572 cannon, and its flagship is the 120 Cannon Battleship S. TRINIDAD.  It begins the game divided on three continents and should facilitate Spain's rapid expansion in the colonies.

Strategy
Spain needs time to concentrate on the colonies and in the best circumstances will come to terms with both Portugal and France.  Portugal begins the game slightly stronger than Spain, so an early war in that direction may go sour; typically, Portugal is more than happy reach a long-term treaty with its only and larger neighbor.  France, too, will often seek peace with Spain to pursue other prizes eastward.  In this situation Spain will be free to concentrate on the colonies, and possibly compete with Great Britain in India.  The Caribbean is Spain's to lose.  If war with France is inevitable then other nations must be persuaded to intervene, otherwise in a Simulated Battle on equal terms Spanish troops have no hope against the much higher quality French.

Conclusion
Because of its Caribbean position, Spain has probably the best long term prospects in Austerlitz.  But it will require patience to develop the colonies, and astute diplomacy to maintain peace in Europe and avoid Colonial wars, at least against bad odds.  Spain is for a player who enjoys empire building and colonial development in a long game that is won at the end when the mighty Spanish economy is brought to bear in Europe.  If the future of Spain is decided in an early European war, its prospects are not as bright.