We already were using AS4134 for inbound and AS4837 for outbound previously because AS4134 has lower latency inbound - the latency would have been even higher with AS4837 inbound as well. AS4837 may just be less congested than before now, possibly initially due to people stopping using AS4387 temporarily like we did therefore the congestion is reduced when its performance was restored - it may degrade slightly over time as more hosting providers start using AS4837 again.