I posted a thread asking which side to take on Roleplaying perspectives a few days ago.
(http://www.gamesas.com/topic/1470943-stormcloaks-or-the-empire-for-rp-purpose/)
I really thought long and hard for many days, trying to amass whatever little information I could find about both factions from the thread and the game. As it turns out, the ambiguity of either side's difference was not intended by Betheda, but it was simply a combination of lazy, poor writing and bad storytelling as it always has been the case of TES games.
In the end, there were almost no differences between both sides, and even the dialogue structures when you take a side are copy-pastes of one another with different topics and subjects. And whoever wins the CW doesn't change nothing, let alone adds SINGLE dialogue in the entire game in which NPC mentions which side won the war. For example, it felt absolutely pointless to support the empire when Elisif doesn't even have a dialogue mentioning their victory in the Civil war afterwards.
This is beyond the point of stupidity and not even worth debating which side to join. Elisif is unaware of CW's result. No other characters beside Tulius, Ulfric, Rikke, and Galmar recognize that the CW is over. I appreciate all those forum members who gave me advices, but I shouldn't have bothered seriously contemplating on the question in the first place.
I spent 150 hours without doing ANY guild quests, main quests, or CW quests because I was absolutely immersed in the atmosphere and vastness of Skyrim's world. Well-designed unique dungeons and epic side quests those saw a huge improvement from linear and boring side quests of Oblivion made me think that Skyrim will offer a true great experience with Main quests and CWs. So I held off playing them as late as possible, and only now did I realize that was a mistake.
The main quests were horribly short and nonsensical. Guild quests were good but felt short, and CW was.... well, let's just say when I realized I won't ever be defeated or attacked, I tried killing my comrades to lose a battle. My side still won even after I killed every soldier on my side. I couldn't lose a battle or a hold.
After seeing these, I went through the whole CW in 2 hours. I switched sides to see if there are any differences, running through the CW in 1 hour this time.
I was a fool to expect any good stories or interactions from Bethesda. Skyrim is still a great game, but I really feel my first 150 hours were wasted on doing dungeons and side quests in anticipation of how great MQ and CW would be.
I didn't even spend this much time contemplating a choice in The Witcher 2... I'm sorry to let off my frustrations to this board, but I'm truly disappointed how CW was handled in general, both in stories and battle mechanics. I don't even know how Stormcloak vs Empire argument could make a debate after playing the CW. Not only it's ambiguous, but there is no real difference worth considering.