Vaas was one of the most memorable characters in gaming for me. Just incredibly well written and performed. The actor was so good; they modeled the baddie on himself!
The bases were fun and challenging although a bit samey and as long as you didn't alert them for reinforcements; it was a bit easy. I definitely agree with the bases being taken over again by spawning enemies just to keep you on your toes. Far Cry 2 was annoying because enemies respawned if you went out of the area by a few yards on the whole island. This was the biggest problem in that game for everyone as you spent 10 mins clearing the way only to come back after 30 seconds to find all the enemies had respawned in exactly the same positions. I'm glad they eliminated this in Far Cry 3 in certain areas but when you blitzed a load of bases; the island became soulless and very quiet indeed.
The towers were just this weird puzzle of getting to the top by crouching, ladders and jumping up stairs and barriers. They become progressively harder but more tedious in time. Hope you don't have to do the same in FC4. Perhaps overtake a bases communications or something where you kill two birds with one stone instead of base raiding and then annoying tower climbing.
I desperately want to see more of the island and not just the base which has been in the gameplay footage.