To increase wireless capacity, the concurrent use of multiple wireless interfaces, called aggregation, can be considered. In this paper, we focus on using multiple WiFi interfaces between an access point and a client, and packet-level traffic spreading between interfaces. Two aggregation strategies, link bonding and multipath TCP (MPTCP), are tested and compared in a multi-WiFi radio system with their Linux implementation. Various test conditions such as traffic types, network delay, locations, interface failures, and configuration parameters are considered. Experiment results show that aggregation increases throughput performance significantly over the use of a single interface. Link bonding achieves lower throughput than MPTCP due to duplicate TCP acknowledgements (ACKs) generated by packet reorderings. However, link bonding is better under long network delay and interface failures since it is fast responsive to links’ status changes. It is shown that different combinations of interface weights for packet spread in link bonding result in different throughput performance, envisioning a spatio-temporal adaptation of the weights. Two solutions, delayed ACK and filtering duplicate ACKs, are discussed for further enhancement of link bonding.