not really lol
cost is another factor to consider, and unless DDen's stuff is competatively priced, it would most likely be cheaper to get the OCPC stuffs (which im sure you already know).
now lets see...do the BI have replaceable barbs? nope. what would be the better option? as far as which rad to get? i think the BI might be a little smaller (you'll have to check the dimensions on your own), but they both look easy to mount to the case, etc. ask how many passes the coolant makes thru that rad, and ask how many parrallel tubes it has per pass (it looks like a 6 tube / 2 pass design, but it could be 3 tube / 4 pass).
as far as how the blocks compare to DDen (and other) blocks, i couldnt say...but that Neptune block has a design not unlike DDen's Maze 1C block (except for the plexi top, and LED hole
). i do believe DDen has addressed the issues with their Maze3's, so cracking shouldnt be an issue anymore.
so...get whats cheaper, unless you're rich, then get everything and tell us how they compare in your system lol.