I ran my H&R Race springs for about a year without any issues. Never bottomed them out or anything like that, but I rarely have people in my back seat. My shocks and struts held up just fine but my roads aren't too bad either. I ran without CC plates with no unusual tire wear as well, but if you're worried about tire wear then it would be a good idea to install them.
Sold - Black 2000 Mustang GT, gone but definitely not forgotten
- Silver 2007 Corvette
Current - DHG 2001 Bullitt