I've only just scratched the surface of iOS 6 on the iPad - but here are my 15 minute thoughts...
1. Although the Maps app looks good, and the text style is very nice and easy to read - The images aren't good enough in areas outside major cities. The areas around my house are a complete blur, whereas on Google maps it is clear. This is quite disappointing, but I imagine it'll improve with time. The POI information on the maps are very well done, and although I can't fully test the Turn-by-turn on my iPad, it looks very nice and clear.
The 3D is quite a nice feature, and does look very good in the city. I'm just hoping that this will continue to be improved by Apple, as the quality of images aren't as good as Google.
2. The extra information Siri can give is very helpful! I might actually end up using Siri in this update! Being able to just ask Siri what films are on, and have it bring up a list with times is so helpful! However, I'm disappointed that it would appear, football information won't work if your team isn't in the Premier League. It showed me the results for the Premiership, but wouldn't give me any information on any teams or scores in other leagues
3. The App store does look nice - Not quite sure I like how the top charts are listed at the moment, but the App pages are definitely improved for the better
All in all, it looks like a solid update - However, the maps are a little disappointing, if you don't live in a major city...