The level of bureaucracy depends on the project of course, but any type of CLA will cause problems for many corporate contributors.

Where I am, policy allows us to contribute small patches to open source projects without legal approval - but only if there's either no CLA, or an existing CLA for a major organisation like Apache that our legal team has already reviewed. Otherwise, mandatory legal review for any and all contributions.

A DCO-based system, on the other hand, is fine by us.