How different is the iPhone 4s to the iPhone 5s?

I'm soon to be getting an iPhone 4s, but was wondering whether it was actually still worth the bother. I would like to know really how much different the 4s is to the 5s. I know the 5s is faster, gets 4g, has the fancy finger print scanner thing, has a bigger screen, better camera and more pixels, but how significant are those things?

What I mean is, is the 4s really, really slow and would make surfing the web an impossible task (like the iPhone 3gs, my mother has one and in the time it takes to load up sometimes I could've walked to the moon and back)?

Is the size of the screen really a big issue?

Is the camera really terrible, or is it okay?

So basically, I'd like to know the major differences between the two, and how much worse the 4s is from the 5s and if it can do the following things and more:

-Facebook
-Instagram
-Snapchat
-Occasionally Skype
-Calling
-Texting
-Whatsapp
-Occasional Internet research (But I mostly use my laptop for that)
-A few games (Temple run etc.)
-BBC iPlayer, 4oD etc.
*May add if I think of anything else*

I'd say yes, the justification is there to upgrade from the 4s to 5s, but to better answer your questions would be to experience it for yourself. Check out a local Apple Store or somewhere you could play around with a 5s & compare to the 4s.

Also keep in mind that the iPhone 6 is expected sometime mid-September & it would be better than both the 4s & 5s.

You've answered all of your questions as far as 'major' differences go except the 4S uses the 30 pin dock connector and the 5 and up now use the lightning connector. 30 pin cords are now a little cheaper. Bottom line both use iOS 7 and the 4S will get the new iOS8 update in October that will debut on the new 6. Also many of these last 4S models also have 4G installed. I have a family member on ATT who purchased one early this year and it does have it. The original 4S models didn't. Screen size is totally a user preference. The camera is still very good and just doesn't have a few of the newer 5S bells and whistles is all. Yes, you can perform all of those still on a 4S. Best luck.

Obviously the 5s will be faster
Better camera
Bigger screen
Etc
I currently have the 5s and my friend has the 4s
The 4s is still a good phone since it is a few years old at this stage
For social networking it will be fine and casual gaming and watching YouTube videos but that's it really
I would advise you to go for an iPhone 5 or 5c if you can you can get them on ebay or amazon for a really good price
Since the iPhone 6 will he out in September along with ios 8 I wouldn't recommend you getting the 4s this will be the last software update it will get. I would hold off until the iPhone 6 is release and the iPhone 5c and 5s will go down in price even ome or just get the iphone 5 or 5c now
I know you probably don't want to wait but in the long run if you go for the 5 or 5c or even 5s first you will get a bigger screen it will be A LOT faster and better camera
It's a lot more future proof
Hope I helped

5S is a 100 times better hardware all around, its not even close.