Carey and Hix (2011) propose that a proportional electoral system with a moderate number of seats per district offers the best compromise between (1) accurate representation and (2) strong accountability. The argument is that there is a district magnitude (DM) level where the trade-off between proportionality and fragmentation of parties is optimal. This DM is called the sweet spot. We explore this proposition through lab experiments conducted in Brussels and Montreal. We find that the probability of achieving a “good” outcome on both proportionality and the number of parties is slightly higher at moderate DMs. We note, however, that this probability remains low.