Not really a complete answer, but just my 0.02 about block finishes...
About 1.5 years ago now, i bought an asetek waterchill kit, and even tho the base of the cpu block was quite shiney.. it was not smooth, it had been machined lapped and actually had quite large grooves in it. i was getting about 35'c cpu with 20'c air, and when i mesured the temp of the water in the system, i realised it was only 1-2'C above room temp (2x200cfm push/pull fans ), so i decided i had to do somthing.
i lapped the waterblock with 1000 grit to start with, but that didnt touch the grooves, so i moved right down to 400 and then went up in 100's to 1200, than i used some Brasso metal polish (i recomend this and Nev-R-Dull for finishing blocks, brilliant results) and when done and remountec with stock "white goo" thermal paste, i got down to 31'c!!!, with Arctive Silver 3 i got it to 26, and now its in my brothers system (on a hotter CPU, in a warmer room (apprx 25'C) with Arctic Silver 5 the CPU never gets above 30, i know this without mesuring temps as i have a little alarm set to go off when it gets that warm
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Anyway, what i am saying is, the block's finish when it comes of the line is of no concern, as you can easily get it up to a mirror finish with a little work.
I have just bought a DD RBX and i am quite pleased with it so far as quality and ease of installation go, but i am yet to put water through it. i do have an Eheim 1260 spare atm (its actually for sale, i havnt even opened the box) and i am gettign an Eheim 1250 during the week and my PSU should arrive soon so i will get some info up.