Meego is quite good..
I have the latest MeeGo running on an old Acer Aspire One (the original A110 8Gb SSD model), although not being a real tablet (by virtue of having a touchpad/mouse, and a real keyboard)
And that keyboard is a real asset, it means that for web surfing, email and IM it is a really good experience! It is loud and cartoony and probably fine for either my mother or young nephews.
I only tried it for a laugh, to see how fast it booted (good'ish) and mostly because I was bored of running Fedora on the A110. I discovered that it has a much more 'pure' linux experience than Android. I have been able to install several apps I need on it (and which are not in the limited MeeGo core repository) from rpm's! Things like SSH work really well, copy/paste etc.. is there by default, a full terminal+shell was already present in the applications menu. :-)
A nice thing is that I managed to install Java, by simply getting and running the binary installer from the Oracle site, it ran first time. And then it ran a Java app that I use a lot (but which is quite fussy about which architectures it condescends to run on) flawlessly. I was well impressed.
There are also some real weaknesses; one is is that it is a 'single window' device, you have to keep Alt-Tab switching to really get multi-window productive (and on a tablet presumably you have to go via the menus; which is not handy at all). And there is no real notification system; popups appear to tell you about events, but once they gracefully fade away nothing remains to tell you that you missed something if you missed it at the time.
If you have an old netbook lying about, this might be a interesting thing to try, and might prove quite suitable for giving to the kids etc. Installation was crazy easy too..
And MeeGo is a fine little OS :-)
In case you are thinking I should try the opposition I confess my iOS experience is limited, but my reference for this is that I have a 10.2'' Android (2.2/2.3 hybrid) Tablet.. One of the first wave of TegraII based devices.. Very, very good..
- without a real keyboard it is not as productive as the A110.
- as a entertainment and web surfing tool it makes the A110 look very poor..