I can't help worry that capacitor removal will result in greater risk of damaging the motherboard pads and traces by keeping them there, until they fail (unless the caps themselves are visibly leaking, and should be replaced there and then once identified).

All these wonderful computers in storage though - are you keeping your older Macs as backups to working ones, or with the hope that in twenty years time they will indeed be your retirement next egg?

I recently purchased some Compact Macs from a man in the bush, who stored them in shipping/packing crate for several years (in the sun, the crate had a cracked window). I think there were eight Macs all up, and every one had cap failures, corrosion and HD/floppy drive failure. Superficially, they all looked fine - it was only with opening them up did the problems become apparent. I was only able to make up two "good" ones out of the lot, and still had to put many of my spare parts in. Therefore I'd consider choosing consistently cool and dry conditions to be significantly more important, as a whole. Without these conditions other components will fail just as quickly, and are much harder to replace and/or source.

JB