last summer I had the muffler removed because it was badly rusted, and it was cheaper than replacing the muffler. I looked at that product, but it ended up costing me less to just have a muffler shop weld in a pipe than it would have cost just to order the part, and I read a magazine while it happened instead of doing an "easy" bolt in procedure on a rusty old exhausted. Its certainly one option though. I recommend pricing out a couple of places, it'll probably be comparable to have it done professionally and be a whole lot easier.
As far as benefits, I only did it because the final portion of the exhaust had broken off of the muffler because of rust. I didn't have my gauges before, so I don't know anything about EGT differences, but mine are now comparable to most other moderately tuned 12v trucks I read about on here, so I assume there wasn't much of a difference. It is a little louder. Though with the windows up I can barely hear it. It doesn't have a really nice tone like a larger diameter replacement exhaust, its just louder than stock with more turbo noise, which is nice in its own right, but don't expect to sound like you put on a whole new system. Mileage hasn't changed, except when I roll my windows down, particularly when driving past some sort of wall . . . mileage has dropped in those instances. I haven't towed with mine, so I don't know what, if any, drone there is towing. Mine does have a resonance between 1100 and 1250 RPM that it didn't used to have, but that is low enough that I rarely am in it.
All this to say, if you want it straight piped, it can be justified, but don't expect earth shattering results. Hope this noncommittal response was helpful.
Travis