How do you manage Gmail with your desktop mail client?

I use Mail in OSX and my primary Gmail account is linked to it. I like that it’s always running in the background, and I enjoy having a desktop email client instead of relying on webmail. However, I’ve gotten spoiled with an Android phone, which groups conversations the way Gmail does on the web. So now I feel like my Mail program is clunky and slow, in addition to being full of unnecessary emails (that could otherwise be grouped together). I use Outlook at work and am happy enough, this is for my personal email.

Do you use a desktop-based email client? If so, what do you use and how do you like it? Have you experienced my problem, and how did you address it?