I prefer as much screen real estate as possible.
Partly because that (for me) usually offers a better combination of chart context and detail at the same time... and partly because when using split screen modes, each of the splits can be a more useful size.
Can't say, relative to your boat, but for example if I had a choice of 2x 16s versus 2x 12s... I'd go for the 16s... and mentally amortize the cost over the period of our ownership. $1/day, or some such.