So here is my game situation.
I just took the sphere, to be truthfull I had to change the game to easy for the halfling encounter, entu and togan chopped apart my best stacked fighter with -17 AC and with the fortress shield it was better for missiles. I just could not bridge the gap of doing 8 points of damage and having entu doing 25 along with the 15 or so from togans arrows. I didn't even have time for my sorcerers to do enough damage on entu before my fighter was chopped.
I have done the unchanged quests, of the strongholds the last is against the shadelord then off to the underdark. Here is the comparison. There is not alot to shadows of amn after the underdark, a few areas then off to the elf city. Normally the planar sphere content is finished or close to it by then. So now that I just took it at such a late stage the normal content will not be done till after the underdark, then there is the content that sikret put in of which I know nothing about. It is highly possible that my party will have to travel and stall for time in order to experience all the content of the planar sphere. I can see the same thing happening with the ranger stronghold as the shadelord battle is one tough battle and I would probably have to postpone that encounter till late. I don't know if I can take the shadelord even now.
It seems to me that a possible solution would be to keep the difficulty of taking the strongholds at a moderate level, then add content for a progressive difficutly level, that way everyone would be able to experience the full contents of the strongholds and the game would have better timing for the average players, sorta like it was for the original game whereas the stronghold content was finished when you were ready to go to the elf city, no waiting around.
Just a few thoughts.
Romulas