Since getting my x758 the only complaint I have is the seat suspension is definitely not as comfortable as the suspension on my previous 445. I think it has to do with the weight rating on the springs. It seems the latest X series tractors have seat springs rated for about 250lbs+. The earlier X series springs were closer to 200lbs. I'm interested to see if anyone knows what the suspension springs on the 445/455's were rated at, mainly the last models like the 00'+. Riding around on the x758 just feels like I'm riding a washboard, and yes I've lowered the tire PSI to 8 in the rear and 10 in the fronts. Now, honestly, I only weight 130 lbs, so I'm pretty sure the seat springs are the issue, it's like riding a short bed dually with no weight in the back lol. I might be interested in buying a seat of the older X series suspension springs off someone if you've upgraded to the later, heavier springs.