What are your thoughts on going to a R5 or R6 from a 5DMkIV. I photograph Aircraft at Airshows mostly. I have a 5DMkIV and 7DMk2 with Sigma 150-600mm Sport lens. I do not do Video at all so don't worry about 8K video side of the camera. I have lots of EF-S lenses and a few Full frame lenses. My goal is to get extremely sharp pictures of airplanes flying at 300mph going in every direction from far away. Can you use EF-S or full frame lenses with adapters ? Is the R5 45Mp sensor that much better than the 20Mps sensor of the R6 for Still photo's and does it justify the extra cost ? I hear the battery life is only 250 shots which seems very low since I shoot a around a thousand shots per day at a big airshow and use two batteries per day on most occasions. The Cost of the new RF lenses concerns me. I dont want to spend $2500 for an 85mm lens. I need a wide angle up thru 600 mm for ground shots up to far away planes and I cant spend $20,000 on lenses no matter how good. What are your thoughts ?