When I got my 28DSBH, my truck was feeling "squishy". After doing some research and help from members of this forum, I decided the "squishy" feeling was coming from my P275/55 R20 tires. So, I put on Michelin LT275/65 R20 Load Range E tires, filled them up to 70 lbs and NO more "squishy" feeling. Just my 2 cents.
2014 Ford F-250 Lariat Crew Cab 4X4, 6.2L gasser, 3.73
2013 Jayco White Hawk 28DSBH
2012 Ford F-150 Lariat Supercrew 4X4, 3.5L Ecoboost, 3.73 (traded)
2005 Jayco 1207 (second PUP)
1976 Coleman Brandywine (first PUP)