Eliot went into a bed about a month ago (i.e. 22 months). his sleep is rubbish, but it's no worse in a bed than it was in the cot! He is in a cot bed and has a bed guard on one side, so there's actually only about 12 " that he can get out of , so there's no danger of falling out. Ben went into a bed at 25 months, and Zach at 23 months. We weathered the climbing out and running for the door. They both did it, but with a few evenings sat on the landing, they got the hang of it (and dh was always more effective at getting them to stay in bed - he'd be up there for about 20 minutes, while I'd be all evening!) Bryony also went into a bed at 25 months, but like your girls, she never got out!
So from me it's a 'yes, if you think it might help'! We didn't have much of a choice with the boys - Ben was climbing oout the cot every ten minutes at bedtime, and Zach spent a night throwing himself out over and over and hurting himself. Eliot started screaming hysterically when I put him in the cot, so we decided it would be less painful to go for it.