I have heard anecdotal complaints from friends that they are frustrated with the location of the SEND Button. If composing a replay to a long message on a laptop, you need to scroll down the page to locate SEND. Why not put one at the top of the message as well?
We are currently working on improvements to the send button toolbar. The change we’ve made is to ensure that send button is always in view so users don’t have to scroll to get to it.