Map is a big ♥♥♥♥ing A+, EXTREMELY well done. The fact that there are still quality GMod Story maps to be found on the workshop makes me happier than a goat's milk nipple. However this is more towards a personal issue rather than the map itself.

If you skipped pass this in the description, then I'll tell you here instead.

If you have a worn-out, $2, found-behind-a-dumpster PC, then it is really important that you keep it mind: the map WILL be laggy. It is EXACTLY what the screenshots look like: if your PC isn't good enough to render a single 4-Story building, then this map is not for you at the moment. You need a pretty damn powerful PC if you wish to run this map flawlessly.
My suggestion:
Subscribe to the map-but don't have it enabled (or at least don't play it yet) until you save up enough money to buy a powerful PC. Once you do that, then by all means-play this map to your heart's content, as I do strongly believe that this map NEEDS to be played by every single living, breathing GMod player in existence.