Gmail for me! I think it comes down to Google-vs.-Yahoo, which I think comes down to 'whose services you use'; and I'm a child of the media (i.e. I don't hear too many shows-etc. making the suggestion that you "Yahoo! It" when you need Internet-information on some set of words!) I use blogger/blogspot (rather than Yahoo!-Contributors), which Google links to Picasa (rather than Yahoo! Images). From there, I take 'the next natural step' and use Google's products-or-suggestions. (I don't even know gmail's POP3-server address to check it with my Microsoft Outlook---my browser's too slow to go look it up; but I'm a gmail-user anyway ... do you know the server-address? (I have an old Yahoo-account (or two) floating out there on the web like flotsam, but it's been years since I checked THEM!)
Actually Both are good Email services company and it has its own benefits of using. It is very difficult to say that which is better. But If you ask personally then I like to use Gmail account.
My first email address was through yahoo mail. I used to like it at first but then yahoo mail started getting really buggy and slow after all of the updates they kept making to the site. So I gave up on yahoo mail and joined gmail and I've never looked back. I love gmail and I haven't had any problems with it so far. I really love the layout and speed of the website.
I have both but I've never been able to actually use my Yahoo. If I do use my Yahoo email, I'll use it just to the truly send one document and not get back to it for another six months or even years. I find my Gmail very convenient. I like how I am able to sync my phone with it. I never lost any of my contacts. I also think that Gmail is very user-friendly. I also have a lot of information in emails on the from a few years back and so I find it hard to make the change. To be honest Gmail is very good
I may be biased with my answer here but for the more than 10 years, I've been with yahoomail. I memorized all the hot keys and the places I need to go to get whatever I want done. For almost 1 year now, I created a gmail account. Gmail is also good but I haven't figured out yet everything that Gmail has to offer. Again, I'm telling you that this may be biased but, I'll go with yahoomail just because it's more user friendly and it has been there for a very long time.
Gmail is much better. It is linked in with other services such as google + and youtube which means I only have to log in once and then I'm logged into the majority of my sites. It's handy because I have a central account that most of the sites I go onto are connected by. I also much prefer the interface of gmail, it is so much more sleek and streamlined than yahoomail.
I use Gmail for two main reasons. The first is the aesthetics of the service. I prefer both the web and mobile versions of GMail to most other email services. The second is that having a Google account makes available so many other services that are well integrated (think sending a large file over email vs making it available on Google Drive)
I've long since spat out Yahoomail for it's atrocious and painfully slow user interface. I remember waiting 1-2 minutes before I can get into my email and after that I still I have to wait for the mails to load. But that's a long time ago and my internet is indeed slow, but when I switched to Gmail, I never had the same problem.
I used Yahoo! Mail for years and didn't have very many problems until about the last year when it felt like I was constantly getting hacked. I would wake up to find that "someone" had sent about a bunch of spam emails from me in the middle of the night. After the second time this happened, I switched to Gmail and have had no problems. They have a great SPAM blocker and I like the fact that there are different folders for social networks, etc. I should not be surprised that I like Gmail better though...I'm pretty loyal to the Google brand. Favorite search engine, Android phone, etc.
Like yourself, I use both mail programs but Gmail wins a higher ranking for me. I am annoy with Yahoo's ads in my mailbox when I am checking my messages and quite frankly the format hasn't change since I first signed up in 2008. The only thing about Yahoo Mail that really change is the color of the background and perhaps options for you to design your mailbox. Gmail is apart of Google and always seem to be evolving. I love how they separate my messages into different categories and as you described, it is silent and not interrupting my time when I am checking messages.
I don't really make much use of my email systems I must admit, but if I had to choose, I'd say that gmail is the better of the two options. I mean, I'm surprised people are still using anything related to Yahoo. Hell I'm surprised that they're still around.