How Big is too Big for a Map?

[PutraenusAlivius]

I've made some big maps (My sort-of-dead CS is divided into four parts. Each part has one map.) and I got some advice.

For optimization, I think that having little detail helps, but destroys the intriguing part of the map. So some small stuff aren't really detailed, but detailed enough. Also, try not use a lot of models with high polygons. For size, I've learned never to go beyond 5 - 10 MB.

Again, my opinions. I could be COMPLETELY wrong.