If you have a lot of big user stories, your velocity will jump up and down wildly. This makes it extremely difficult to tell when a user story will be done. Breaking down your huge user stories into smaller ones will help you smooth the flow and give you a clearer picture.
I’m a firm believer of release early and often. If there’s more than 10 new commits in our code repository awaiting release, I start to get uncomfortable. Whether it’s extra “inventory sitting on our shelves” instead of in your browser, or the uncertainty of “going live” with a bunch of new stuff and then running into a problem. Which change caused the problem?