Sorry to resurrect this old thread but I have some experience with this setup and wanted to add some info.
The car was a '97 Passat TDI bought with 90k miles on it; I ran it up to 216k and then when I sold it I got 4 offers, two full price, sight unseen, from my craigslist ad. The engine didn't smoke except on cold startup for a minute like many of those diesels did. The engine used a couple of quarts per 10k miles due to the poor treatment of the previous owner or a bad break-in. I installed the kit and at one point experimented with never draining the oil for 40k miles; the oil analysis I was using said that was OK since the additive package was kept fresh with the top-up oil and the base stock never wears out on synthetic.
I don't know if I could have done as well without the kit. I do know it feels good that the bypass continually removes any grit from the engine, not just at oil changes as in the usual setup. Also removes blowby products and a lot of soot if you have a diesel. Your oil at the end of its life will be cleaner than a conventional filtered car with just a few hundred miles on the oil, since full flow filters let relatively large particles pass through. The kit is around $300 and I know people spend that much on silly shit for their vehicles, so why not for clean oil? Maybe it doesn't pencil out like the others here say, but what is peace of mind worth anyway? If you like your truck...
Needless to say, the extended changes (if you bother to change at all - use oil analysis to be sure) certainly justifies the use of best quality synthetic oil, at no added cost. If you try this strategy with synthetic *without* a bypass filter, that is questionable because the oil will get pretty dirty over twice the normal change interval.
Keep in mind you can buy this kit once and remove it and put it in your next truck too - OR you can charge more for the vehicle when you sell it because it shows you cared for it. I didn't remove mine because in that car putting on the adapter plate was a huge pain due to poor access. But it made my oil changes a lot easier as the filters were mounted vertically and I could even pre-fill the filters before installing them. I would change the bypass filter every other time I changed the full flow.
I also installed a bypass filter on a Sprinter van, not the dual, but just the bypass. This is easier because the hoses are smaller and the mounting options better. If you like the stock fullflow setup or can't find an adapter for the dual remote, this is the way to go. Also, this way removes all worries of a pressure drop through the hoses as someone mentioned might be possible with the dual remote (I don't really think so because the pressure relief valve in the engine controls the pressure, not the hoses).
My only question is, what does this do to my 100k warranty on my shiny new truck??