Ok. I've done HOURS of research with no real decision yet for my needs.
I have an 02, 6 speed, with DDRP-02 lift pump, & torque dog module but stock on everything else. The tuner works really well on low end probably a lot like a smarty does from what I've researched.

My delimma:
I just need a little more umphf pulling my 8500# 5th wheel. If I don't hit about 2100 rpms pulling bottom of a hill, the truck falls on it's face.
ie:
3.55 gears
bottom of hill at 70mph+ puts me at 2100 rpms or better and I'll top most hills at 60-65mph and 1900rpms.
Bottom of hill at 65mph puts me around 1900 and I'm downshifting and clinging on to life by the time I top the hill.
My options:
-Keep Bully Dog and buy some RV275's (100hp)
-Upgrade to Smarty and see if it does a little better between 1800-2000rpms when towing
-add more boost. I hear hx35 and boost elbow will gain a little more boost and could make the difference. I like this option too b/c it's really cheap!!!

 

Are you running the hills in 6th?

 

I am. If I drop back to 5th I can't keep the truck up to speed with a fully loaded 5th wheel maxing out probably 9500#'s. We don't have really steep grades and my egt's never get more than about 900. I would be running like 2400 rpm's if I ran it in 5th on the grades and it sounds like armageddon in 5th gear up in that range...

 

How's your fuel pressure?

My trailer was a good deal heavier than that and my 12v didn't have trouble maintaining speed. Granted I've got an auto, but similar 3.55 gears.

 

fuel pressure is good. idle-almost 17psi, WOT on a steep grade empty-14psi