My experience is that if the rims are strong ( the "aero" aluminum rims that are 27 - 30 mm deep are good examples - the extra depth can make them very strong), it's possible to make a low spoke count wheel that's just as strong or stronger than a traditional wheel with lots of spokes and a box section rim. The Neuvation M28 Aeros are an example of this approach - it's a strong reliable wheel (I used one for more than 10k miles, and it's my trainer/emergency wheelset now). However, I was stranded when I did break a spoke after a recumbent crashed into me just over the finish line at the Tour de Tucson a few years back - I couldn't get the wheel true enough to ride back to the hotel with the limited number of spokes remaining.
The reason I like my more traditional wheels is that when something goes wrong (and it eventually will if you ride enough) the traditional wheel is more likely to be kludged together to limp back home (wrapping a broken spoke around the adjacent one), and to be repairable at any bike shop.
I used Mavic Ksyriums for a while, and they were very strong - the Aksiums seem to have the same reputation. Ride them until you wear them out or they start breaking, then worry about replacing them.
JB