Earlier quoted context omitted.
Yes, to the point that it is very easy to crash Thunderbird if you blindly hook it into your GMail account.
I've never had that problem. I have plenty of other annoyances with Thunderbird (so much that I'm paying for what's essentially a custom UI), but it's usually stable. It hasn't complained when I've hooked up a half-dozen accounts, collectively about a half-million emails, and it did everything reasonably quickly.
Let the record show that Thunderbird no longer becomes unresponsive for me when accessing my GMail account, must have been a glitch on that day when I first set up GMail in Thunderbird.