Slow to connect when checking email. Sometimes (most-of-the-time) cannot connect. The old system was functioning great, why change it? It was not broken! Very sluggish in processing information! It's overall unacceptable!
Try clearing out your browser's cache/browsing history. When you have done that, close out the browser and re-start it in a fresh session. If that doesn't do it, then try using a different browser.
The auto-fill should use contacts from the address book, or that you have sent or received emails from even if they are not in the address book. Check your settings and make sure you have both send and receive options enabled. From the Inbox page, click on the gear icon in the upper right corner, then on Settings. Under "Mail settings" you will see "Common". It's in there.