I have been using and playing with a number of bow (or almost bow) and
SLE kites in the past year.

What I have found is that SLE is better in term of stability (remember
the flatter is less stable formula with Seasmik) and jumping performance
(the Sled Boosting effect). On the other hand, the bow is probably
better in term of speed performance (less fabric, lighter kite for same
construction)

So at one end you have SLE like Waroo, the other end, you have bow like
the Crossbow, and a bit compromised Waroo-Pro (this is between SLE and
mid-SLE), SwitchBlade, One, etc.

The flatter the kite, the more concave the trailing edge need to be
(probably only a true bow kite need to have concave trailing edge) or
use a trailing edge bridle like the Seasmik.

It is very interesting to observe that the flat kite revolution that
started with the Seasmik, the Nexus (a bit too foil oriented), this
experiment: http://www.template-toolkit.org/tpc5/kitesurfing/index.html
(has both curve LE and bow trailing edge) , the Flexifoil curve leading
edge (probably taken from the previous experiment), the bow patent
application from Bruno and ended with the SLE.

Personally, the main reason why I want a SLE/bow kite is for this reason
http://sports.groups.yahoo.com/group/kitesurf/message/67005 (and the
market in 2006 has probably showed the preference).

Hung.