X-Drive VS BlitzBuck

I am considering one of these for a TEC,
~6.5V @ 2A from 2 lithium cells

What is the max vout of these drivers?
Which one has the lowest Dropout?

Will the new BlitzBuck V4 use the same IC as the V3? / would one work better than the other?

EDIT:
Also does anyone know what a good PWM frequency for a TEC would be?
If I have room, I might just make a 555 cicuit for it...

Well, yes, the BlitzBuck V4 uses the same IC as the V3. The max vout of this driver is 10V (I would say 8V though for safety purposes). The BlitzBuck is again, a buck driver, so it technically doesn't "have" drop-out. But, it can only go up to 85% of the input voltage.

Thanks for the info,
Is the blitzbuck Synchronous?
What is the max duty cycle of the IC?

EDIT:
Wait let me guess, 95%?

Yes, the BlitzBuck is synchronous. The max duty cycle is about 92%.