Been towing the HHR now for almost 6 years (20K miles), no problems. Did just have to put new struts, lower plates, hub bearings and sway bar ends on it, but at 84K+ miles, figure I got my monies worth out of those front suspension parts I had to replace, plus my GM extended warranty covered most of the parts/labor.
I looked at the Honda CR-V and Jeep Liberty back when trying to decide what to tow. Went with the HHR mostly based on price..it was $1000s less than the Honda or Jeep.
With the HHR now out of production, will try to hang on to it until we upgrade to a DP, and then will have more towing weight available. Right now I'm at 5K lbs, and the HHR weights in at just under 3200 lbs...