iptables. 32 or 64?

[kitepilot at kitepilot.com]

Hello World: 

I run my firewall on a LFS box.
Everything on it is compiled from source.
No bells and whistles, only the essential software is installed. 

The hardware is 64 bits but I've been running 32 bit OS.
This time around I am wondering... 

The question is:
Is there any advantage to compiling the whole iptables enchilada in 64 bits?
Should it be avoided? 

Please note that the 'normal' rules like 'more than 4GB and/or 32-bit-adobe' 
do not apply here, what I am looking for is whether filtering/marking will 
be faster/slower and (if known) why. 

Any ideas?
Tnx
ET