My Sonic's steering is firm, crisp, and responsive at all speeds, as were the three I test drove over the couple months leading up to purchase. Testing something in the "highway turbulence" thread, I even did a half mile or so behind a semi with my hands hovering a quarter inch off the wheel.
If you aren't getting these results, your tires may be at fault, steering did improve with my aftermarkets (and that's what the turbulence test was with) but more likely, you have an actual problem that needs to be addressed.... I did several thousand miles with the stock tires, and those other Sonics I test drove also naturally had stockers, no complaints.