Upload & Sell: On
...Let us know how you like it...
All signs point to "yes".
...I would frankly sell my 70-200 II and 100-400 for that one lens if it is as stellar as the reviews have us believe.
Not me. I'll be keeping both of them. The 70-200 MK II is a peerless, medium-telephoto, fast zoom lens for events and general purpose photography, in almost any conditions. The 100-400L is a peerless, medium-long telephoto zoom lens for general purpose photography in decent light; it's a great, lightweight companion to the 24-105L, for daytime walkabouts. The EX 120-300/2.8 OS is a bit on the heavy side - same weight as my EF 200/1.8L.
If satisfactory, the EX 120-300/2.8 OS will fulfill many roles of the EF 300/2.8L IS that I sold earlier this year (woe is me*), plus a few more (maybe). Hopefully, it will be part of a dynamite combo on the sidelines; EF 70-200/2.8L IS II on 1DX, plus EX 120-300/2.8 OS on 1DIV, with or without 1.4xIII Extender, as required. Also, it will go in my airline carry-on bags a lot easier than my 500/4L IS.
Anyway, time will tell, and so will I.
*it moved to Sweden; that move paid for my X-Pro 1 system.