One reason I decided against getting a 70-200mm f/2.8 was because I would need to add a 2X TC
(or at least the 1.7x) to get to a reasonable focal length needed for aviation photography, which would degrade the IQ
to or near the point at which a slower zoom with more useful focal range would actually be the more practical choice(to say nothing of the added cost). Since I rarely shoot in low light, 2.8 isn't needed. Plus I don't get hung up on extreme subject isolation- f/5.6 @ 300mm provides enough should I want that.