I mostly shoot landscapes and low light sports (fencing and dog-agility), but when traveling I like to take wildlife photos as well. I'm heading to Costa Rica in a couple of months and I don't want to haul a giant lens around. I actually want to keep my total camera bag size down as much as I can so I will actually carry it all with me on a regular basis. This is why I recently sold my Nikon gear and picked up an a5000. I don't mind carrying a bit of extra weight, but I'd prefer to keep that down too. Right now, I'm looking at picking up a Nikon 180/2.8 and a teleconverter to use for wildlife. I figure this lens could then do double duty with wildlife and low light sports. I've looked at the various 300/4.0 lenses and they all look a bit big and heavy. My question is, does anyone use the 180/2.8 with teleconverter for wildlife? If so, how has it worked out for you? And is there anything else I should be looking at?