You actually want to watch parry with bushido. We had recently had changes where in Bushido did not hurt parry with a shield. However, with the revert it goes back to OSI mathematics.
Without drowning in the math, basically, the higher your bushido after 80 the more bushido hurts your chance to parry with shield. If you use a two handed weap you don't get this "hit". BUT since a shield gives one more item for bonuses, you want the shield and do NOT want bushido.
For an example, below demonstrates parry +/- bushido:
120 parry , 0 bushido: parry with shield=35% , parry with a 2-hand weap =5%
120 parry, 120 bushido: parry with shield=5%, parry with a 2-hand weap=40%
160 parry, 0 bushido: parry with a shield=40%, parry with a 2-hand weap= 5%
160 parry, 120 bushido: parry with a shield=15%, parry with 2-hand weap= 52%
260 parry, 0 bushido: parry with shield = 70%, parry with 2-hand weap= 5%
260 parry, 120 bushido: parry with a shield= 40%, parry with a 2-hand = 80%
As you can see, parry + bushido offers great parrying with a 2 hand weap; however, this would take away an item for bonuses (+to hit, +defense, etc) and you really want that extra item for more defenses here. So, the way to go on this shard ATM is to have 0 bushido and high parry to increase block % and give an extra item for bonuses. Now, if they change it again to remove the penalty for using a shield with high bushido, then the story changes.
EDIT:
Oh, and to use the numbers from V above:
150 parry and 150 bushido:
parry with a shield = 5%
parry with a 2-hand weap= 57%
So yes, with his numbers of 150 in each, you have a much higher chance to parry with a 2 hand weap. BUT again, this takes an item out of the picture for bonuses, so you have to take that into consideration when deciding which way you want to go.