I am a fan of both lights. As for beams what are you looking for? The 16 has a fatter hot spot and is designed for shorter range. The 22, despite what it looks like on Fenix TK22 page is more well defined than than what they show, has a hot spot close to half the size. The total beam pattern width out of the 22 is greater than that of the 16. Honestly the 22's profile diameter is VERY wide and quite useful. Use 2xCR123 in the 22 and you get 1000 lumens.
The TK16 has a double walled tube design which is extremely strong. The 16's new double switch tail takes getting used to and being a new design does not have all the kinks worked out of it. You may or may not get a 16 with a properly functioning double switch tail. There are reports here on the forum of the 16's double switch tail either malfunctioning or totally failing. On the other hand some get copies of the 16 and have no issues.
My opinion, get the TK22 2014 edition. It is reliable as a hammer, has roughly 20k CD throw a MASSIVE beam with zero artifacts, well spaced modes, excellent aluminum grip ring and is a design that has been around a few years and is proven. I want a TK16 but already have equivalent size/output/profile lights such as the Eagletac T25C2 XP-L HD. Am waiting to read about Fenix improving on the 16's double switch tail before I buy.