It should be noted that both the Money Market and High Yield Savings require a $5K balance for the 3.5% rate to apply. Balances below that only get 1.0%. The Savings account has the advantage of only requiring a balance of $50 to avoid a monthly service charge. The Money Market requires $1500. Their product comparison page has more details about both of these.
Should your insurance agent be your banker?
I just found this article at Bankrate.com. It's a little old but I found it relevant for this post. Thanks to the Gramm Leach Bliley Act of 1999, insurance companies like MetLife are allowed to offer banking services. MetLife isn't alone, Statefarm and Allstate have their banks now. I just checked the savings rates they offer, and they're not very competitive.
The article didn't give any real problems with banking with your insurance company. You shouldn't expect local bank branches from them. They are essentially online banks. The one tip from the article is to stay with the top-of-the-line insurance companies with strong credit ratings.