Jenn is right, the chair needs some reprogramming. my old arrow 2g with GBs used to get stuck on the threshold of the front door of our house. the wheels would stop and when i gave it more gas it started lurching side to side violently. i later realized that i had my torque level way too low. i turned the torque and power level to 100% on all drives and the problem went away.
the TDX SP you demoed was just programmed better than your SR. have the tech come by with the programmer and tweak everything till its to your liking. it may take a few visits with the programmer to get it just right. read
this article ....it helps explain all the programming parameters and what they do.
