For an R5 owner who misses the instant before the shutter press, the Mark II’s pre-capture addresses a specific timing problem. With pre-continuous shooting enabled and the shutter half-pressed, it can retain up to 0.5 second before the full press. Its electronic-shutter burst also rises to up to 30 fps from the R5’s up to 20 fps, giving more frames across a short action sequence. Those maximum rates depend on the shooting mode, lens, exposure and battery conditions.
There is a stills tradeoff. Independent testing measured a slight reduction in base-ISO dynamic range on the Mark II compared with the R5, with electronic-shutter shooting more affected. That matters when the priority is preserving a high-contrast scene rather than catching a fleeting action moment.
For longer video takes, the optional CF-R20EP fan has a substantial but specific result. At 23°C from a cold start, recording 8K 30p with the standard temperature threshold, the Mark II body was estimated to record for about 26 minutes; with the fan on high, about 106 minutes. Prior live view, warmer surroundings, battery life or card capacity can shorten a take, and the fan can be audible in the recording. Its benefit is much more modest in 8K 60p RAW and 4K 120p. The test compares the Mark II with and without an accessory; it does not establish better body-only endurance than a firmware-updated R5.
The Mark II is worth considering when pre-capture addresses repeated timing misses or that fan-assisted recording setup fits a recurring job. The actual replacement cost needs to include any required fan, LP-E6P battery and suitable recording media; full video-mode access requires that battery. If those needs do not recur, an R5 that already does the work remains a sensible camera to keep.