If you choose Inova T1, you might consider the following (explanations from a guy at CPF) :
"The T2 provides more light from the same batteries for a longer time because it uses a buck circuit instead of the boost circuit the T1 uses. Buck circuits are more
efficient than boost circuits. Since they get more voltage than they need
(6V in the T2) to drive the Luxeon, they can draw lower currents from the
batteries which greatly helps to get more energy out of the battery. A boost
circuit gets too little voltage (3V in the T1), thus it must draw *more* current
than the Luxeon needs to boost the voltage.
There is really just one reason for 1-cell lights: size, in every other respect, it's a disadvantage."
So if size is not so critical, a T2 will give you more light, for a longer time, than a T1, with a same set of 2 x CR123 batteries.
_________________________
Alain