iRule Performance Question

Hi everyone,

I'm looking at using an iRule to consolidate the amount of IPs we expose to the web for some of our webservers. I see a lot of other people do this on here and created a simple iRule. I search for HTTP_Request and route to pools based on the string that comes across in HTTP_Request. I've got the iRule created and it works great but my question is related to scale.

How many websites can I safely put into this iRule before it starts to get bogged down and affect performance? My plan is to set an arbitrary limit of 50 sites unless someone recommends using less. The point behind using 50 is that we have nearly 200 websites we want to use this iRule on but if someone makes a mistake, I don't want all 200 websites to go down.