What chassis is better

The one that feels the best to you. Without being too snarky, this is really a personal choice aside from vetting chassis with known issues.

No way to reasonably answer the question, even if one assumes you are only comparing diesel pusher chassis.

Both Spartan and Freightliner make a range of chassis from entry level to tag axle high end.

Would be kind of like asking about Ford vs Chevy with the Chevy being a Cavalier and the Ford being an LTD. A Chevy Caprice and a Ford LTD have more in common than a Cavalier and Caprice.

Had a Freightliner on our last MH, have a Spartan on this one. Both are fine.

I'd be more concerned with suspension (IFS vs straight beam) and rear vs side radiator.

Depends on what you are looking for, a gasser or a pusher

10 airbags…Prevost, Newell, Foretravel, & Monaco S-10 Roadmaster

The new Ford chassis (2020MY?) is much better than the old one.