The impact of our plugin on the performance of your website depends on your usage of the plugin and on the resources that are available on your server.
Some of our customers have hundreds of feed sources importing thousands of items without a significant decrease in speed. Generally, the amount of resources consumed is directly proportional to the number of feed sources you have active, the number of feed items being imported, and the number of items already imported; all that times the frequency of imports.
As a preventative measure, if you are planning to do a lot of importing, we recommend a hosting plan with at least 128M of memory available for PHP. Also, please bear in mind that in order to utilise available memory resources, the WordPress memory limit has to be adjusted accordingly.
We also recommend staggering the importing of feed items on your site, as explained here.
