I prefer a smaller, lighter laptop such as the 14" MBP but the cooling performance of the 16" is quite impressive too. You'll also get thicker heatpipes with the 16". No thermal throttling and barely any fan noise when stressing the 16" laptop with heavy workloads.
If you will be pushing your M1 Pro/Max laptop for longer periods of time the extra 200 dollars spent on the 16" makes sense. It all depends whether you will primarily keep your new MBP on your desk at home or the office or take it with you on the go. The 16" will be much cooler and quieter under heavy workloads. The 14" will perform nearly as well but you get much hotter CPU temps and more fan noise. This is what the MaxTech YT channel found in their M1 Pro MBP testing recently. Here's a comparison of the fan sizes between the two.
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The 14" has a 1.2 lb. weight advantage and is slightly thinner.
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