Going through again

I am about to go though the game again but this time am aiming for a complete run, weapons, dark aeons, penance, etc. In short I want to do pretty much everything that can be done with the likely exception of completing the sphere grid with all characters!

I've used the standard sphere grid enough to know whats going on and am tempted to use the expert grid now. I just have some concerns. Mostly I am concerned that the expert grid may stunt my abilities in the long run making it (impossible?) to kill penance (no zanmotos). Is this a genuine concern?

Apart from that are there any major bonuses to the expert grid? I'm really quiet happy with the characters styles as they are (I don't see auron as a mage) with the exception of kimahri who I'd like to customise a tad better than last time.

So is there any point in me using the expert grid or should i justs tick with the standard?

Expert Grid is better for normal/plotline play, since your stats grow much faster than normal.

The Normal Sphere is better for the long and involved, time expending players, since it has more nodes.

Im questioning whether those 'extra' nodes are really required at any point in the game, penance included.

Well, they certainly help. Of course, this all depends on how high you want your HP, or whether you are willing to go around and replace most of your Accuracy and Evasion with Luck nodes.

It's a toughy. I'd like to see where the expert grid goes but at the same time I don't want to waste my time getting stuck in to the game. Would it really be necessary to go around replace accuracy and evasion nodes? Are there not enough points on the grid already?

As mentioned, replacing Eva/Acc for Luck is mostly so you boost your HP value past 9999.

Im not following you. Boost your luck to increase your health?

Increasing Luck and largely ignoring Accuracy and Evasion means you're using half as many nodes. These unused nodes can be replaced with HP nodes.

And this is a requirement to beat the dark aeons and penance? Sheesh! Does he really require so much prep to face? And isn't removing evasion and accuracy nodes going to weaken you?

Unless you know what you are doing, high amounts of HP or preparation are recommended.

In FFX, the game's internal system works so that having a 255 Luck Rating COMPLETELY replaces Accuracy and Evasion (which must be left at base stats, around the 35-45 area) in order to have every attack of yours hit, and every enemy attack that can miss, will not hit you.

However, Luck nodes are a long and cumbersome process at best (Greater Sphere/Earth Eater).

You could just Zanmato them all, but that'd be boring.

Luck affects critical hit rates, the chance of hitting the enemy and the chance of dodging enemy attacks. With 255 Luck you can have base Accuracy and 35 Evasion and you'll hit/doge everything that's possible to hit/dodge.

Be warned, the process for raising Luck is very slow. You'll be fighting Earth Eater and Greater Sphere over and over.

I think I probably going to go with the standard sphere grid. It's probably the best choice in the long run as I am going for a 100% game completion. Thanks for the advice.

You could use normal or expert sphere grid and still complete 100% of the game,so it doesn't make any difference(i've done it with normal & expert).
In order to beat Penance you must complete more than once the sphere grid.You do that with clear spheres.You also need 3 characters(or four) to have more than 30000 HP.And high stats,celestial weapons,and the right armor(ribbon,auto-life,auto-haste,break HP limit).
Be prepared for many long hours of leveling.