Just got myself a WZR-1750DHP from Amazon.
Tried the stock firmware, was quite impressed with the performance and features provided, only draw back was SSID2 only supports WEP encryption, and I do want WPA2 on SSID 2.
Was always a big fan of DD-WRT, decided to give it a try, flashed the following two images:
Unfortunately the WAN performance was not very good at all, it's kind of limited to about 30MBps throughput, apparently hardware NAT was not enabled / support on DD-WRT firmwares.
No SSID2 vs slow internet, I've decided to go back to stock.
Procedure for going from DD-WRT back to Stock 2.22 firmware:
(1) Download 23709a (buffalo customised DD-WRT firmware) from Buffalo
(2) Extract the .zip downloaded from Buffalo, locate file wzr1750dhpd-v24sp2-23709a.bin, and update to router, selecting erase all settings.
(3) Download v2.22 firmware from Buffalo
(4) Extract the .zip, and locate file wzr_1750dhp_eu_222
(5) Update firmware from 23709a to EU 2.22. Be patient as the process did take some time, and router might restart several times.
Done, back to stock!