Yes there is a difference between the 2. They have different tapers on the studs and a DLE will take more angularity then a TRE.
I am running all TRE's in my crossover steering setup. I run a bent draglink so the TRE's in the draglink don't see that much angle and the TRE's in the tierod don't see squat for angle obviously. I have been running my TRE's for over a year with no problems at all.
I built my crossover system to use 1 TRE. All four of my TRE's are the exact same part number. They are all right hand thread TRE's. This way I only have to carry around 1 spare TRE. It is also the one of the most common TRE's out there. It is a standard Chevy 7/8" TRE. Part #2234R. I got mine for $27 each at the local parts store and they have a lifetime warranty.
The only downside to using all right hand thread TRE's is that if I need to adjust my tierod I have to pop one end out of the knuckle to adjust it. That is no big thing though in my opinion.
A bent draglink has to have one end popped out to adjust it no matte what so that is a non-issue.
Harley