Just attempted to drill thru a poured foundation (10" thick maybe)with a regular 1/2 craftsmen drill, took me 30 minutes and my arms were killing me. Cheapo $10 bit to boot. Due to the work I do, I will need to drill thru foundations periodically so I need a hammerdrill. Question is, do I get a rotary SDS or a regualar hammerdrill? I won't pretend to even know the difference as I have never used either. Suggestions appreciated.