This is definitely one of those personal preference things. Infmom apparently loves desktop email clients, and Geek and I hate them. I used desktop clients for years - Outlook, Thunderbird, Pocomail, Eudora, Evolution, etc. I was so glad when Gmail arrived and I could dump them. I don't feel the desktop clients give me ANY advantage over webmail, and actually think the desktop is worse. But... that's me and everyone is different.
I know that I have switched many of my clients to Gmail and away from desktop clients, and they've all been very happy and don't miss the desktop client at all. Whatever infmom does with her email, she likes the desktop and nothing I or anyone else says will probably change her mind, as nothing is going to change mine. She will continue to feel empowered by her desktop client, and I will continue to feel I have been unchained!
I've had problems with desktop clients that probably color my outlook (no pun intended!) on the topic. I'll stick with my cloud and she can stick with her desktop. My internet is rarely down here, and if it does, I have my cellphone I can access it from, so I've never been locked out of my email, so the desktop would be of no advantage. When I delete, I really mean to delete, and I don't want various computers having different emails on them. It's not bitten me yet, so for me, it's fine.