Both are good phones but the summary of the professional reviews on the W810i beats out the Pearl by a little bit:
Sony W810i - http://www.productcritic.com/product/48-sony-ericsson-w810i
Blackberry Pearl - http://www.productcritic.com/product/47-blackberry-8100-pearl
I am a cingular customer currently not held in a contract, I can cancel at anytime without fees. I have a decision to make between upgrading through cingular and purchasing a Sony Ericson w810i ($75 after rebate, +2yr srvc) or privately purchasing a Blackberry Pearl ($150 used for 3 days, owner upgrading to treo).
I know these two phones come from different worlds, one being gadget oriented and the other being a professional(ish) device.
I currently do not have a data plan for internet usage with Cingular.
I currently own a SE z500a for over 2 years. Outdated "smartphone", kind of beat up, could use an upgrade.
I'm not so much a gadget person per se, as I don't own an MP3 player but wouldn't mind the dual functionality included w/ the 810i.
Talk time initially played a key role as the w810i has a spec of 8 hrs to the 3 w/ the pearl. I've done some searching and found little coplaints on battery life with the pearl however.
I'd just like to see what the owners of these phones might have to say about their likes/dislikes of these devices.