Reach Weapons & Armor Spikes?

[Diarmuid]

I'm unsure of how this works mechanically.

I know I can threaten 5' with the armor spikes for purposes of AoO's and whatnot, but if I have attacked with my reach weapon in the round already, would I then incur TWF penalties for any attacks I made with the armor spikes?

[PairO'Dice Lost]

I'm unsure of how this works mechanically.

I know I can threaten 5' with the armor spikes for purposes of AoO's and whatnot, but if I have attacked with my reach weapon in the round already, would I then incur TWF penalties for any attacks I made with the armor spikes?

You take TWF penalties only if you actually gain the extra attacks from TWFing, not just for wielding two weapons. If you switch out weapons for AoOs you don't take the penalties, just like a fighter with four iteratives from a +16 BAB could attack with a sword, then a mace, then the sword again, then the mace again without any penalties.