Huh. I never actually did the math before, but: there's 32 symbols on my (US) keyboard. Upper+lower+number gives a baseline 62 characters. This gives us a password space for brute force attacks of

    10 char alphanum: 62^10, or 8.4e17
    10 char alnumsym: 94^10, or 5.4e19
    11 char alphanum: 62^11, or 5.2e19

One extra character instead of needing to type symbols into my phone, with nearly identical complexity? Sounds good to me.