From what I've seen the world is VERY similar to sr3. If my question yields true, it's definitely going to be a bargain bin purchase for me

I think the game switches between the city of Steelport from The Third and also a virtual version of the city so they might make some changes in the virtual one to make it seem more unique? Then again this is still speculation and we won't really know until the game is out (unless Volition has announced anything that I missed).

It's the exact same world with alien stuff... even the models/graphics are the same.

From what I've seen of the game, it's the exact same Steelport from The Third, just with more vertical additions. The Saints HQ tower is destroyed but now there's huge alien towers in the city.

Unfortunately the city looks more brown compared to 3's purple neon look and there's no day-night cycle, it's only night.

It looks pretty similar from all the trailers and such, but from what I hear much of it has been altered or destroyed. I've also heard that an open section of Washington DC is also a part of the game, but it's unclear if that's just the intro/tutorial area before you're zapped into the virtual Steelport. I don't think I'll mind that it's similar that much as I'm confident Volition knows we don't want the exact same city and need more variation in a sequel. So long as it's still funny, full of dumb shit, and has a fun story I don't mind if most of the city is the same!

The exploration in Saints Row wasn't really the appeal to me, it was the humor and the fun toys they gave me to play with. So even if the map is the same I don't really see why that matters.

Given all the talk about Saints Row 2 recently I played a bit of it and wow. That world really was much more memorable and interesting than that of 3. If you meant that "exploration in Saints Row THE THIRD wasn't really the appeal to [you]", then I very much agree. But the world in 2 is really what draws me in more than anything else as of right now.

I have only played The Third actually.

And yet the city in Saints Row 2 was largely recycled from the original Saints Row, from what I recall. Same city with an altered map.

The general structure of the city was, but it was still mostly built from the ground up again and was doubled in size. Plus it completely redone all of its pedestrians, whereas SRIV is very clearly recycling all of that stuff from SRTT.