I'd like to thank you all for your input, I appreciate it! This forum constantly amazes me with its wealth of knowledge.
I indeed am not riding cobbles but thanks. The super low profile and narrow rims of the past that were used on Paris-Roubaix were probably favored by riders because their flex made them feel smooth compared to a more rigid rim. Good if you ride cobbles, bad if you race crits, something I plan on doing with these.
As for the Kinlins, I was trying to steer clear of them since I have not heard too much good about them from my bike wrench buddies. Likewise, I guess the IRDs are out of the picture now too... Instead, I now have my eye on a pair of Pacenti SL23s. They have the wide profile of the A23s, depth of the IRDs, and a very attractive weight @ 450g. Much more pricey but I figure if I'm going handbuilt, I might as well do it right.
BDop, may go that route since the I have never had integrity issues with a front and radial is very simple to do (probably why factories use it too). Plus, the before mentioned cool factor.
With a wide, stiff rim like the Pacenti SL23, I'm guessing the consensus is that 32 spokes is a bit overkill for a 150 lbs rider? However, one thing I did like about the Ultegra hub is that it has a steel axle rather than the alloy axles you find on most hubs nowadays. The extra weight, I believe, would be inconsequential because it is so close to the axis of rotation. However, the durability increase would be substantial, especially for someone who rides on some pretty miserable roads at times.
If I do decide on going 28h for the rear wheel, I am open to suggestions for a hub. Just discovered Novatec hubs, and they look pretty attractive given their price, weight, and ability to source steel replacement axles. I did, however, appreciate the peace of mind Shimano internals gave me with the Ultegra hub. How is the reliability of these nicer OEM quality rear hubs? I realize they come in a ton of different brands/rebadges, mostly front the same handful of manufacturers in China/Taiwan. I've had Formula hubs that were garbage but from what I understand, Novatec is quite a step up from Formula.
Even found this factory tour on Pinkbike.
http://www.pinkbike.com/news/Making-...-Hub-2013.html
Pretty neat. Got me thinking about a new MTB wheelset build...if this one doesn't bleed me dry first.