is that latency coming from routing to your upstream network or the packet scheduling itself?
Also, I am aggregating 2 4G link which might not help since both links send large packets of data infrequently if I understand correctly. Maybe aggregating 2 wired link would have lower increased latency cost.
In the end, I'm getting up to 40Mbits of bandwidth instead of being stuck with my 3MBits adsl link and I'm pretty happy.