Upload & Sell: Off
StillFingersz, now that I see that 1.6x1.6 MP is required, I can see why a 400mm 2.8 plus 1.4x/2x teles are required. Most of the people on this trip were shooting with 1DX or 5d Mk3, using 300mm 2.8 and 1.4x/2.0x or 400mm 2.8 and 1.4x. One guy was even shooting with a 600mm 4.0 and had 1.4x and 2.0x teles. I have a pretty good kit, but I felt like I went to a gun fight with a knife on this trip!
The 7D is just over three years old. Hopefully the 7D Mark II is just around the corner, with Digic 5 processor, ISO up to 51200 (vs the existing 12800) and increased dynamic range (overall and in terms of holding it longer before losing a stop of range per stop of ISO). That would solve most of my problems, although I wouldn't object to the 400mm 2.8 with a 1.4x tele, if 'Santa' felt so inclined!
Skibum5, I tend to shoot a lot in the 370 to 400mm range; doing more 'action portraits' rather than environmental shots of wildlife. On a fair number of occasions I would not have objected to even more reach. It is not unusual for me to shoot wide open for the bokeh even if it means slight drop in IQ. I can't profess to say I understood all of what you said, but given what I said in this post (including this latest post), I am gathering you would agree that the APS-C sensor is where I need to stay.