There is a tiny impact on performance because you're using resources to backup the logs. But it's really tiny. If you're already at 99% resource usage, adding this might be an issue. But the answer is not to skip the ability to do a point in time recovery, the answer is to address why you're using 99% of your resources.
"The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood"
- Theodore Roosevelt
Author of:
SQL Server Execution Plans
SQL Server Query Performance Tuning