I live in Japan and recently bought WZR-HP-AG300H, it has been around almost 2 months now.
Anyway except from the HW difference, there is significant throughput difference between using 5GHz and using 2.4GHz band as there is high intereference on 2.4GHz band as used by many people around.
With 2009 Macbook Pro, I could get 100Mbps on 5GHz band (A band), but thoughput decrease around 50-60 Mbps on 2.4GHz band when connecting internet.
When uploading to LS-V2.0TL connected to WZR-HP-AG300H,the 2.4GHz band speed is around 50-60Mbps again but I can reach 150Mbps on 5GHz band,
Hope this helps...