So I finally pulled the trigger on the R5 Mark II after years of shooting with the original R5 and some older EF glass. The new body is absolute magic when it comes to the autofocus but Im finding my current setup is really holding back that new sensor. I was out last weekend trying to track some fast moving birds and my adapted EF 100-400mm II just felt... sluggish? I dont know if its the adapter or if I'm just finally seeing the limitations of the older motors when paired with this crazy fast AF system. Its weird because that lens was a beast for years.

Anyway I need to figure out a dedicated RF wildlife setup before my trip to Costa Rica in November. I'm going to be doing a lot of hiking so weight is a factor but I don't want to sacrifice too much reach. I've been looking at the RF 100-500mm obviously but then there's the 200-800mm and even those crazy expensive primes if I can justify the cost to my wife lol. The 45 megapixels on this sensor are so unforgiving if the glass isnt sharp enough.

Here is what Im looking for:

• Budget is around $3000 to $5000 max
• Needs to be manageable for 5+ mile hikes
• Must keep up with the R5II eye tracking without hunting
• Ideally works well with a 1.4x extender if I need extra reach
• Weather sealing is a must because of the humidity where Im going

Ive heard some people say the 100-500 is the gold standard for versatility but I keep seeing these amazing shots from the 200-800 and the extra reach sounds tempting for smaller birds. But then the aperture on the 200-800 is pretty slow especially in the rainforest canopy. Has anyone here put both through their paces on the Mark II specifically? I want to make sure I'm getting the most out of the new processor. Is it worth stepping up to something like a used 400mm DO or just stick with the modern RF zooms...