Well I've bought it...
And I really like it. I love the autosend feature for the merchants, that has to be one of the biggest plusses. It runs a hell of a lot faster, the 'improved interface' thing mandead mentioned is really useful, and one thing that definately helps is the stability hits that are mentioned when you're asked to help an ally in a war. That always got me in 1.3.... And, I don't know whether this is true, but the AI seems a hell of a lot more aggressive, they've been in more wars and gained more provinces than me, and I'm usually the warmongerer!
I love most of it, but there were a couple of things I noticed. Firstly, the stacking armies thing. Thankfully, as I tested the NA with a saved game of Milan, the smaller nations around me didn't do much of this. When I had moved armies away from my collection of provinces around the capital though, France started to move armies to the border between us. I think Provence had like, 4 supply limit, and they had around 20,000 men there. Yeah, it did make me laugh. but if it helps the AI be more aggressive, which something has, I'm not complaining too much. It's a little unfair, but it makes for a much more challenging game I guess.
Second thing was royal marriages, suddenly it seemed as if most of the nations around me had changed to a government I couldn't marry with, but this may have just been my ignorance.
Lastly, alliances. Have they expanded the limit or something? I can't make any when I have more than 3, but they other nations still make the offers sometimes. Not that this is a bad thing, I think it's better to expand the limit, although I prefer to keep to 3 or 4 now. Where as before having a negative relationship with an ally wouldn't scold you, they now tend to call you to war and abandon you.... Which is a little more realistic given the bad relations.
Lots of great features, and I'm very happy with the purchase. Those bad points don't bother me too much, so it's not much of a problem.
Thanks everyone for the advice.
