Well, as the title states I got my first custom tune today. First little history on my truck...

I bought my truck new in July 2013 and deleted her in October of 2013, just 3 months after purchase, right after it's first oil change @ 5500 miles. I started with SIMS and a FLO~PRO DPF delete pipe. That step alone was a night and day difference in performance and MPG (2.5 MPG gain) from stock.
At about 7500 total miles I added a RaceME tuner. Running the 80hp setting made a huge difference in throttle response, overall power and another 1.5 - 2 MPG gain. I really liked the way the truck drove on this setting but it felt a little harsh on the tranny when pulling our camper. This was the point where I started looking for H&S XRT Pro tuner.
At 18,000 total miles I finally found a used XRT at a price I was willing to pay. Originally I was going to use just the box H&S tunes and purchase the Overdrive software adder from H&S and call it a day. But then I found out that Ray Rich (Double R Diesel) is just a few hours away from me. He is getting tons of great reviews on the Cummins Forum for his custom tunes. It turns out that the MCC unlock (which you have to purchase from H&S so you can add custom tunes) now allows tuning almost all of the tranny parameters without purchasing the Overdrive software. The Overdrive software is $300 on the H&S website... MCC unlock is $200 + RR's custom tune including tranny tuning was just a little more than that so this ended up being a pretty easy decision.

I saw/felt very little difference between the RaceME tune and the XRT Non/ATT box tunes on my truck. This is not the case with my new DoubleR Diesel custom tune!!! It is almost like driving a different truck!! The truck accelerates and runs smoother, throttle response is much quicker and the shifting... oh the shifting is much MUCH better in every way! I used to have to go into manual mode when driving through the 35-45 MPH zones in town to keep from lugging around in 6th gear all the time. Ray's custom tune fixed all of that.
Upshifts and downshifts are firmer but not harsh like Tow/Haul mode can be when running unloaded. Having downshifts occur when you would expect them to is something I have really missed.

A big thanks to Ray @Double R Diesel for taking the time to write a set of tunes specifically for my truck and my needs!!