Just read this thread and I must agree with Zap, Gilbot, and skinnee. This kit is for complete WC'ing newbs that are intrigued with watercooling but are overwhelmed and confused by the sheer variety of options the individual pieces present.....radiators, cpu blocks, tubing, pumps....and the list goes on. For someone like that, this kit fits quite nicely.
I entered the watercooling market several years ago, having read about it for quite a while and wanted to try it, but was unsure how to go about it for the first go round. I ended up settling on the Corsair Nautilus system. Why? Simple setup, all-in-one out of the box experience, and by a brand I trusted (I pretty much use only two brands of memory, and neither have OCZ anywhere in them.......let's see, Corsair---no OCZ there.....Mushkin---nope, no OCZ there, either. )
After setting up the Nautilus, and it was quite painless, I had a very positive experience with it. Of course, within 3 months, the radiator had been replaced with a Black Ice Stealth (I'd have used a Swiftech MCR120, but this was when the 120 had fixed 3/8" barbs and they were too tall to fit inside the Nautilus's box.) I then upgraded the cpu block with a Swiftech GT.
Since then, I've assembled my own loops and currently have a simple cpu loop--an i7 920 under water using an HK 3.0 cpu block with a TC 120.3 rad and S-Flex fans, a DDC2 pump with XSPC top, and Primochill LRT tubing. But if it were not for the initial positive experience I had with the Corsair Nautilus, the ease with which it went together, I may not have gained the confidence to begin to grow in the WC'ing hobby.
I'm not saying the Nautilus, nor the new Corsair unit, are the best performing units in watercooling, but for the target audience, complete and utter newbs to watercooling but with an itch to get into it, albeit with as little drama as possible, Corsair continues to fit the bill completely. And that's the whole point of systems like the Corsair units.....to provide quality cooling and drama-free entry into watercooling.....not to give the outright best watercooling performance out there. They're leaving that to the other manufacturers to provide the equipment for and the forums like here and on XS populated with experienced hobbyists to provide the guidance.
As for why a lapping service? It may be as simple as the individual is unsure how to do it properly and would rather pay someone else to do the job correctly.....I know that if I paid someone $20 to lap a TRUE, I'd darned well expect it to be done right or they'd do it over. Or it may be the person just wants it done when they open the box...just install without getting the "pleasure" of a half-hour's worth of work and getting their hands dirty.