String Trimmers

Hi, I have a 326LX that I bought in 05 and still running strong with no problems. I just purchased a 232L and fired it up and they appear to be very different. I am sure some of the technology has changed but it doesn't seem quite right. The pull cord is different (strange mushy initial pull but works) and there is a little more plastic. They appear to both have the same carb a ZAMA C1Q but total different sound and response from the throttle. The 326 is quick responding with no "dull" response however when I give the 223 the gas it seems to start out a little slower and kind of dull then picks up. Is this normal? Maybe breakin? It's brand new so I want to make sure it's right and not settle.