Any time I buy fresh lima beans, the cashier gives me a look like I must be fucking crazy. I tell them the same thing I tell you: just trust me.
Canned limas suck. Frozen limas are all right. Fresh limas are awesome. Mediterranean cooks know this. Southern cooks know this. Somehow everyone else forgets.
You have to shell them, but that's easy enough - hold the pod in both hands, twist it, and it'll usually pop right open.
The mealiness of limas comes from beans that are too old or overcooked. Ideally they're creamy - there's a reason they call them butter beans in the South - like cranberry beans or favas. They're a little sweet, though not like peas - but sweet enough that they pair very well with tomatoes or corn.
I'm sure I'll make succotash this week, I'll try to remember to take a photo and post again.