In my case I don't notice any cpu spikes, but my server has 32 cores, of which ADS uses 16. Do you notice worker threads going up in the ADS Configuration Utility?
The temp files can indeed be configured to be in a different location using the ADS Configuration Utility. It requires a restart of the ADS service though so be careful that you don't have any users on when you do it. In my case they are on a different drive which is not included in the replication job.