The only drills my dealer currently has in stock are the C12 and the T18. No C15 or T15. So, I can't do a "live" comparison of 2 tools of the same voltage in the 2 different configurations. Makes it impossible to decide which I prefer... weight, balance, general feel to my hand, etc. I know I can buy, try and return within 30 days, but that's more trips and more hassle AND delay. And, how many times can you do the 30 day deal anyway?