[wiltw]

IMHO the usefulness of spot meters is a little over-rated, and certainly, three are two more than enough.

Spot meters are so overrated that

1. I have some form of spotmetering in six of seven metered cameras (Olympus OM-4, Bronica ETRSi, Olympus G2, Canon S95 ...all except the Olympus OM-1 which I purchased new 35 years ago, Canon 40D, Canon 5D).
2. with my handheld meters, my Minolta Autometer Vf incident meter has a 5 degree spot attachment, and my Minolta Spotmeter F reads one degree, so when I have these along, virtually every camera I own is accompanied by spotmetering.

When one understands how meters work, spotmetering is very useful to have.