Well with the new 10.1 the fonts or size of fonts have become smaller, whatsapp now has its own heading in the hub. Not sure about twitter as again i dont use it all that much, i have blaq which is a much better twitter client imho and worth the £2 or so it costs.
As for facebook??, i dont use it...only time i use it is on my laptop or pc at work and even then i log on maybe once every few weeks...i actually hate facebook so try to avoid using it as much as possible.
Blaq is much better for browsing the timeline, etc. But I still use the twitter integration in the Hub for DMs and replying to mentions. I really liked the consistent look and feel throughout the Hub that 10.0 had and is now broken in 10.1, for no good reason that I can see.