Hi Sean, I'm using the Hamilton pendent with 14k lamp.
That PAR thing seems debatable... It probably has more to do with lamp selection and reflector design. I would think two bulbs of the same spectrum side by side without reflectors, that the higher wattage one would "win". But I like the compactness of the DE pendent very much.
If you wanted to get really whiz-bang technical, a 400W lamp with a Pacific Garden Supply Lumenarc III (or Lumenarc A3 mini) reflector would blow away the competition. But they are not the prettiest reflectors, you'd probably want to have a canopy just to sort of keep the overall presentation of the tank nice.
http://www.pacificgardensupply.com/products.asp?cat=2
There was talk a while ago about a group order for these reflectors. If you're not in a hurry to get something set up you might want to investigate this route too.
The only thing is that these are very large reflectors and probably require a little creativity and DIY skills to get mounted.
I liked the idea of a pendent because it was plug and play. All I needed was something to hang it off, so I made a hangman style thing and it's worked out well. Simplicity has its pluses as well. I wasn't sure whether to go 250W or 400W. But in the end what decided it for me is that I hope to make this cube tank a second tank, so I wanted to keep its electrical costs somewhat down. I.e., if I'm going to run 400W's then I want the 400W's to go over the SPS tank. This tank in question is just my species setup for my ritteri plus maybe a bunch of softies and other LPS that wouldn't fit well in a high flow SPS setup (if and when it ever gets done).