Alex
Arcane
PorkaMorka
While what you are saying is true, that only becomes an issue if the GM wants it to be. And if that is the case, the GM will probably find a way to screw with you no matter the setting. Any given plane should have dozens of portals leading to it from Sigil, at lest. And if the campaign is to be played and box style, the GM won't change the way these portals work unless he has a very good reason (the adventure demanded it isn't a good reason). If you want to, you can have the city of Sigil lead to thousands of different, mappable areas, each more complex, big and with more interesting features than any published setting of AD&D.
Now, you do have a point. The published adventure frequently where pretty railroady, and the description of the planes focused only in a handful of interesting sites, so to make such a campaign, the GM is really on his own. But a few of these sites could get your imagination going and some of these adventures could get you more familiarized with the planes, so the Planescape setting, as a product, isn't all bad.
While what you are saying is true, that only becomes an issue if the GM wants it to be. And if that is the case, the GM will probably find a way to screw with you no matter the setting. Any given plane should have dozens of portals leading to it from Sigil, at lest. And if the campaign is to be played and box style, the GM won't change the way these portals work unless he has a very good reason (the adventure demanded it isn't a good reason). If you want to, you can have the city of Sigil lead to thousands of different, mappable areas, each more complex, big and with more interesting features than any published setting of AD&D.
Now, you do have a point. The published adventure frequently where pretty railroady, and the description of the planes focused only in a handful of interesting sites, so to make such a campaign, the GM is really on his own. But a few of these sites could get your imagination going and some of these adventures could get you more familiarized with the planes, so the Planescape setting, as a product, isn't all bad.