Switching to a 4 stream router from a three stream can provide more range.
Extenders work by receiving and retransmitting data. If this is done with one radio, it takes twice the air time, so you get approximately half the throughput.
Some newer dual-band extenders are able to receive on the 2.4 GHz radio and retransmit on the 5 GHz (or vice versa). This avoids the throughput reduction and can provide higher extended throughput. But there are many variables.
I think B&H has the 2600 in stock. Will grab one and see how it goes. Unfortunately, I think they have a 15% restocking fee if it doesn't work out.
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