So apparently you find the power steering to be a nice thing. Good! In terms of ride I ended up putting suspension under the seats of both my mowers. I also put the XB200 high back on my 324. I added the arm rests to the 540. Too much elbow work to make that practical in the 324. Part numbers on the suspension Am148403. M166745 bumpers, and depending on the height of your present seat bracket sometimes a M146750 is required. Some bolts and nuts are needed too. My spine appreciates the $300 I spent.