[Asterisk-Users] ExternalIVR vs AGI

[Daniel Salama]

I have an Perl AGI script that acts as an IVR for my Asterisk box.  
Basically, it simply plays audio files to the caller, collecting DTMF  
input and logging every DTMF input into a database table, simply to  
document every step or option selected by the caller.

One thing is that in addition to playing audio files, it also, at  
some point, plays SayUnitTime command.

This IVR has constantly about 20 simultaneous callers 24x7.

Would it be more resource efficient to migrate this to ExternalIVR?  
What are the pros/cons of using ExternalIVR vs using my Perl AGI.

Thanks,
Daniel