you would get the same or better system IMO
the diesel site unit filters all of the fluid that goes in to it
unless there is a pressure issue then it bypasses (i won't bore with specs)
unlike the OEM remote filter that bypasses most of the fluid
if you leave the OEM pan you still get OEM filtration
the diesel site site unit is nice if you didn't replace your coolers
and had a tranny go out
now switching to the 08++ internal pan filter is great but it's not really "Improved" is it ? it is just using another ford "MY" part where it is not specified for use
another thing maybe Mark would comment on is the apparent fact that if you do an 08+ pan and filter unless you change the cooler lines to an 08+
you have to run the TP filter in the filter manifold otherwise the fluid will not hit the coolers ( path of least resistance and all of that )
It's definitely the cheaper way to go to upgrade to the newer pan and filter. I get what you are saying by "not specified" it may not be for my truck but the 08 - 10 used the same trans with that pan and filter. If I upgrade to either setup I was planning on still running the TP filter anyway. It's there, they're not real expensive and it can't hurt having one more filter even if it doesn't filter 100% of the time. As I'm looking at it right now I haven't had one issue with the original setup. So, I'm not sure why I'm considering doing anything different as it's worked well for 115,000 miles. If it ain't broke don't fix it!