I have eight 10" pots with two tomato plants in each, and they went out yesterday, but under plastic sheet.
They'll stay like that for a several days, so it's a 'clencher week' for them. I did the same last year, and they survived the awful Spring we had down here, so time will tell! (Got six reserves in the GH just in case).
The sweet peas have been out in their planting bed for three weeks now, and the broad beans have flowers, so we must be getting some sort of luck somewhere down the line! I don't put runners out yet as they've only just started to germinate, and anyway, I always sow a reserve pot from last year's seed in case of a late frost!