Here are pros and cons for #Estimates vs #NoEstimates. I don’t judge. I believe that there is no general rule for using these, but you need to listen and to help client/team/managers to make the decision which is the most useful for the product/project.

#Estimates: Pros:

• Gives stakeholders (rough, more or less) idea about features and project size;
• Ignites the discussion within a team;
• Team is learning through process of estimation

Cons:

• Estimates are usually wrong;
• Time for a team to estimate is a waste;
• Estimations in time

#Noestimates Pros:

• Force small (comparable) size of user stories;
• No time (waste) for estimation – start working immediately;

Cons:

• Client is blind for deadline;
• Needs great trust in team;
• possibly no discussion in planning phase;
• possibly big user stories in sprint breaks the concept;
• User stories need to have business value – sometimes splitting user stories are loosing business value.