Ave. I came to play EB using BI after I was told that the AI was a bit smarter. In fact, I never used the vanilla BI, and only came from the official RTW directly to EB. So, I was expecting to play some night battles and all.
But until now, there have been no nght battles in my camapigns, nor skirmishers swimming thru a river to take their enemeies by surprise in a bridge battle. As for the schieldwall and schewmtrph thing, I never encountered it, but it might be caus I only play eastern campaigns.
So the only positive differences i could point between playing EB with RTW or BI are the naval invasions, which happens more oftenly with BI, and maybe, a smarter BI on a strategical scale... I'm really not sure for the tactical one.
On the contrary, some intersting points seems to miss, like the reinforcements delays, wich were making some battle much more exciting (and sometimes, really frustrating, but this was good for the roleplaying). There is another one, but I don't remind it right now (I had a tough friday night...).

I would really like to have some different opinions from othr users of the BI expansion for EB.