Well the five year warranty seems to last 5 times as long ... makes it better in my book, unless you'll be spending a year overseas diving a lot. Also, afaik the international models use metric scales, so you need to convert the display.
I have the Aqualand Duplex in titanium. Had the steel model first, then upgraded. It's lighter to wear, and corrosion is less of a worry. I choose the Duplex over the HyperAqualand because I use a Mac, and Citizen doesn't support that platform. There is a programm available now that will do that, though. Also, I find the analog/digital combo visually more appealing.
Either one is just a gauge (no deco calculation), so either one will make a decent back-up for your Cochran. The HyperAqualand has more memory and a (lousy) backlight ... .
I switched from the Citizen watch to a DiveRite Nitec+ watch/deco computer a little over a year ago, and like it much better. Can be used as a gauge, or two mix EANx computer, good memory, great backlight, everything is accessible from the watch without a PC (downloadable option).
Another alternative is the Suunto Mosquito, both of them are pretty close in price to the high-end Citizens.