The OP has Legacy Aeris loudspeakers (a design that requires bi-amping) which according to at least one Legacy dealer really likes high power amps. The OP wants to know if the Benchmarks in bridged/mono mode will have trouble driving the Aeris. The responses from people with actual experience using the Benchmark in mono configuration say that the amp should perform well. Other people with no experience with the amp beg to differ. The OP decides to go with the mono Benchmarks. The outcome really shouldn't come as a surprise being that Audiogon is primarily a subjectivist audio site. Experience trumps speculation, even when the speculation comes from informed sources.
I hope the OP will let us know of his experience with the bridged Benchmarks.
I hope the OP will let us know of his experience with the bridged Benchmarks.