Less warmth - yes, makes sense.
Less encumbrance sounds like far more trouble than any possible gain.
This would result in stupid tricks like dunking backpacks in acid to get the best set of armor.
Also, many armors would have to increase encumbrance rather than decrease it when damaged. Plate armors, anything on eyes etc.
Less coverage would only make weak armor even weaker.
However a cap on coverage could be fine. For example, any armor lightly damaged armor could have a cap of 90% coverage and tattered armor only 60%, but armor that has less than that would keep its original coverage. This would not affect low coverage armors (good), while affecting the high coverage ones (also good).
Less storage would be incredibly annoying, so no.
Any other values I missed?