Shin HW, Yoo HN, Bae GE, Chang JC, Park MK, You HS, Kim HJ, Ahn HS. J Int Med Res. 2016 Jun;44(3):405-18
Online searches of popular databases resulted in 14 randomised controlled trials being included. Overall, leak pressure was higher with ProSeal, but i-gel was faster to insert, had lower incidence of blood staining on removal and sore throat.
Link to abstract