I find that my wife's Ipad 2 is great for internet surfing, and using other social media. It’s definitely a much better alternative for traveling than laptop.
But trying to type on it is a pain IMO. I used it many times to post on BITOG and if you want to get more elaborate with your posts, like partially quoting someone, trying to get a link, copying and pasting, etc. is very time consuming and tedious.
This is most likely true for all tablets as nothing can really replace a full keyboard and a mouse.
Also, the browser has this annoying scrolling issue where if the page is not 100% loaded and you try to scroll down, it will bump it back up, very annoying.
Another thing that annoys me about iPad is its form factor. Sure it's looks nice and slick looking, but the flat backside is a pain to hold for a while in your hands and is very slippery. Putting on a cover helps, but it adds to its already hefty weight and the slick machine becomes bulky.
I can't say how the competition fares in that regard, but I think the back side of the iPad should be redesigned for more comfortable grip.
Edit:
These are my thoughts about regular iPad, iPad Mini will be probably much better and less tiring to hold as it's smaller and lighter.