I purchased an Allegro Open Road 35 ft FRED last August and am very satisfied with it. As to diesel noise, that is not a problem with this model. I hear more road noise than I do engine noise. The engine is mounted low in the front and consequently takes up little room in the cockpit and it seems to be well insulated to suppress noise passing into the cockpit. No problem with normal conversation in the cockpit. I have not driven a comparable Ford or Workhorse chassis so cannot give you a comparison.
So far I am getting around 11 mpg on the rolling highways of eastern Texas. Some of our friends have DP's and complain of the same handling problems that I experience with strong winds. I previously drove a 1 ton Duramax PU pulling a 5th wheel with a total GCWR about the same as the Allegro and toad. The PU and 5th wheel handled better than the Allegro does as one would expect. I have not driven a DP with air suspension so I can't really compare it with the FRED but I am not disappointed with the handling of the FRED chassis.
