Just recevied my Series 4 yesterday. Have used the Series 0 since it first came out. Kept resisting the upgrade because I felt like I couldn’t justify the money given the 0 basically did what I needed. But man, I really enjoy the Series 4. The screen size is awesome (44mm) and it’s just blazing fast compared to what I had before. All kinds of features available that weren’t due to limitations of not having OS 5 for the Watch. I purchased and received within two days from Target. Not sure why people are waiting to buy from Apple where there’s a month wait when you can buy immediately from Target (with 5% with Red card). If any of you are on 0 and thinking about waiting to upgrade, just do it. Now that I have the watch I’m really happy.