So comparing the two models, 9550 and 9520, the network specs seems to be exactly the same except that the 9550 adds CDMA/1xEV-DO support.
Now this confuses me a bit. Does that mean that the 9550 will connect to a GSM 3G network like Rogers if unlocked? Check the specs below to see what I mean.
9550
Type
GSM Quad-band phone capable of global roaming (850/900/1800/1900 MHz)
CDMA dual band (800/1900 MHz)
UMTS European/Asian 3G (2100 MHz)
Yes, exactly the same as the 9530 will connect to Rogers/ATT/Tmobile, if you want.
Some additional configuration is needed to get the browser and maintain the EDGE signal, see the "Storm Unlocked on ATT and Tmobile" Sticky Note at the top of THIS 9500 section.
If given the choice, for Rogers, get the GSM device (9500/9520) for much easier setup.