Optimistic / Pessimistic kinda depends on your point of view though. While the truth of the Election may be "pessimistic" to those who hate God, it is optimistic to those who love Him.

I think the same sort of thing applies to Amillennialism. From my point of view it is optimistic because the Lord never abandons the people but preserves them and even causes them to multiply even when the whole planet hates them and tries to vanquish them! And to my mind, the Postmil "golden age" is less optimistic because the righteousness achieved suddenly falls apart, and when the King comes to take the throne of "the place we have prepared for Him" (kinda sounds opposite of His promise to do that for us, huh?), suddenly there's this huge army to oppose Him! Man's righteousness fails again.