Staff Mastery and Wizard of the Spiral Tower

[Fedifensor]

Also, yeah, +1 AC isn't a HUGE deal, but when you start stacking it with everything else wizards get, it starts getting ridiculous. The Iron Man build is one good example.

Iron Mage, actually.

Regardless of whether you allow a character to gain the AC benefit with a longsword, a wizard can gain the staff bonus one-handed and still use a shield. If you don't let the mage get the bonus with a longsword, they'll just go into another Paragon path with no real loss in effectiveness.

 

[Tony Vargas]

One of the advantages - a major point, really - of Corellon's implement is that it allows you to use a melee weapon as an implement (no more needing two magic items to get an enhancement bonus with all your powers and your basic attack, etc). The staff is /already/ both an implement and a weapon. So you already get less of a benefit as a staff wizard for going WotST, because you don't need to turn your implement into a weapon. If you also lose your Implement Mastery benefit...