My opinion on the chassis upgrade introduced for 2008.
First of all, it's better, period. So what I say next, keep that in mind.
The question is, would the rig you are considering benefit from the improvements. For the biggest & heaviest of rigs, I would say "Yes" to increase the extra load of people and supplies you want to haul along. But shorter/lighter rigs, then maybe "Not So Much" spending a lot of money for those 2008 improvements.
Our 2007 E350-V10 chassis rig is short and 9200 pounds, fairly light weight so having the 2008 E350-V10 chassis with so much extra cargo carrying ability would simply translate into a bit of a rougher ride.
I personally would consider a 2009 chassis before a 2008 to get the more functional updated Ford interior. As pretty as our older oval flowing dash board is in our 2007, it's not fun to have my wife's electronic gadgets plugged into the 12V outlets which makes shifting gears tricky for me. The plugs stick out so far that I can't shift gears without giving it special thought. I have been considering adding a 12V outlet close to the passenger which would immensely help me out.
Here is our 2007 dash board. Note the location of the two 12v outlets, both in a bad location for shifting gears.
