BRAD'S COMMENTS:  The one Federation space station featured in the STSTCS that does not appear on screen and therefore does not seem to have any basis in canon, the Alamo is like all defense outposts in that it is the Maginot Line of Star Trek weaponry: huge, bristling, capable of swatting away even the largest of battleships in a single blow, yet unwieldy in combat and quickly overcome by numerous and/or maneuverable opponents.  Unlike the Spacedock station, the Alamo is actually capable of movement, but only after a limited fashion.  At 10 to 1 the Alamo cannot sustain movement across the map sheet without seriously cutting into its power allocation for weaponry and shields.  Conversely, with shields and weapons fully energized the Alamo is one tough sumbitch of a fighting machine--a fighting machine rooted in place and as liable to outmaneuver enemy starships as an 18-wheeler is liable to outmaneuver a horde of Cooper Minis.  So while it is mighty tempting to employ the Alamo in any game scenario (at least if you're the Federation player!), in practice the Alamo is a troublesome playing piece and unless your scenario involves a Romulan or Klingon assault on a Federation colony world, the Alamo doesn't have much practical purpose.
        Moreover, consider the Alamo in the real world.  Space is vast and distances are impossibly large.  Any defensive line that covers an interstellar border is going to have to be made up of units swift enough to patrol the area to the point of sensor saturation, and able to respond en masse once a border breach has been detected.
        The Alamo would make a rotten deep space monitor in that, once contact with the enemy was made, it could not give chase.  Any enemy fleet wishing to breach the Federation border might as well stay at high warp and fly right around the Alamo's outer weapons radius, knowing that the Alamo cannot pick up and chase after the intruders.  Also, since the Alamo is so big and expensive, it is unlikely the Federation could build enough of them to sensor saturate even a tiny portion of its territory.
        Even if the Alamo remains in planetary or solar orbit, as seems to be the case according to the FASA writers, the Alamo cannot cover all areas of planetary or interplanetary space at all times.  If an enemy assault force wishes to take a planet, it need do nothing more than insert itself into a matching orbit on the opposite side of the planet as the Alamo, landing troops and attacking ground based installations while the planet itself acts as a shield against the Alamo's sensors and weapons.  A cloaked Klingon or Romulan fleet could easily slip into a given star system, assume a matching orbit opposite an Alamo, then de-cloak and start beaming down the troops.  By the time the Alamo got word from the ground that an attack was underway, it would probably be too late, and the Alamo itself would suddenly be cut off as a defense outpost with nothing left to defend.
        The Alamo's best real world function would probably be that of an armed and armored traditional space station, able to act as a secure waypoint between groundside and ships docked in orbit.  This makes sense for colony worlds and starbases in contested or hostile areas of the Federation frontier, where space stations would be vital parts of colonial development, therefore making them prime targets for raiders bent on disrupting colonial efforts.  Ideally a space station like the Alamo would serve as home base for a small flotilla of cutters, corvettes, monitors, or even light destroyers, all of which would patrol the colony system and act as mobile interceptors while the Alamo itself served as the final, strongest link between the relatively helpless colony on the ground and their orbital supply chain.
        See more of my comments on space stations and defense outposts at the page for the Klingon Z-4 Deathgame.
        I also infer that such sizeable constructions as the Alamo enjoy lengthy operational lifespans.  So, I have added an additional set of stats that bring the Alamo up to date with technology available in the interim between the era of Kirk and the Era of Picard, which will allow it to better stand up to the more advanced weaponry available to aggressor governments in that same time period.

From the FASA Star Trek FEDERATION SHIP RECOGNITION MANUAL, circa 1985
Alamo Defense Outpost
Notes:  The Alamo Class defense outpost was first placed on location on Stardate 2/0811.  Since that time, 287 of these units have been positioned, usually in orbits around whatever planets are vital, serving as a defensive ring or wall.  Alamo Class outposts, capable of withstanding a tremendous amount of punishment while delivering powerful offensive blows, are the best deterrent to Klingon aggression.  Alamo Class defense outposts are built on location.  They can be moved by several specially-designed Samson Class tugs.