Except for one little issue: the 'power-on' draw issue. Most Eurorack modules don't have this to a major degree, but there's some major offenders out there. The Roland Aira modules are one example that're particularly egregious, and the vast majority of tube modules (not all, tho) have a big power-on draw, sometimes over twice the normal operating draw.
Even so, a multitude of little power-on issues can accumulate into a big one. My rule of thumb, drawing from amateur radio experience (where current draws can change quite a bit during basic operation) is to exceed a specified draw by at least 1/3rd. So, for example, if your totalled operating spec is 500 mA, make sure you can supply at least 750 mA. The extra amperage won't be a problem (it's a measure of capacity, unlike voltage) and having the reserve will not only avoid power-up problems, it'll also let the P/S loaf along with less heat and component strain, making that part of the system last longer.
-- Lugia
Thanks for the advice