>if you have insufficient funds they'll take out a margin loan
That's not my experience with them. I've had them as a checking/brokerage account for 10+ years. I tend not to keep much money in checking so I run into timing issues once a year or so - where a check I wrote will present before the funds to cover it arrive in my account. I've definitely had them pull from the brokerage cash, but not from savings. They have never opened a margin loan to cover it.
That's not my experience with them. I've had them as a checking/brokerage account for 10+ years. I tend not to keep much money in checking so I run into timing issues once a year or so - where a check I wrote will present before the funds to cover it arrive in my account. I've definitely had them pull from the brokerage cash, but not from savings. They have never opened a margin loan to cover it.