Hi Carlos,
Based on your comment about ignoring HD, I would consider it a balance of whether you need additional coverage versus the type of clients involved and their output power plus applications being used.
There are caveats to consider such as (accidentally) creating an asymmetric link budget should the clients be of lower TX power capabilities compared to the now bumped up AP power. This may or may not be a problem, indeed some clients will enjoy seeing the AP traffic (especially beacons) at higher strength resulting in less scanning being triggered for those on the coverage edge. Another thing to consider is the type of traffic and applications being used - bumping the power up might get you an additional X metres of coverage, but is it still usable at that distance?
AP type/antenna pattern is also a consideration - if you are trying to maximise coverage area you need to be mindful of the downtilt pattern vs. a pure omni pattern.
In other words, the possibility of creating an asymmetric link versus performance at the edges versus putting in additional coverage needs to be balanced.
Regards
-jeff