OK I know nothing about BB but what I have read on this forum and others, if you use your phone for work emails alone then the X10 does not seem as synchronised as the BB phones are.
But saying that I run two company's one a decorating business and the other a powerkite school and so far the X10 is a great work/social phone for me.
I have one Gmail account and one web based email account so I use the phones email for the Gmail and simply have a bookmark on the desktop for the web based email addy, I use facebook as a tool to pimp both my business's and the android facebook app and widget is great for this (I just wish you could set up multiple FB accounts on the phone) I also moderate a popular powerkite forum and pimp my kiteschool via other forums and this phone is the best one I have used for updating and pimping on the net. If a student has done well I can get some video footage or a picture and upload it to their FB page, youtube or email it to them on the spot and if the school freestyle team is out and going huge I can do the same to pimp the riders.
Android ver1.6 and 2.1 are worlds apart but... Ask anyone who owns an X10 to go on to a phone with ver2.1 and they will struggle to tell you the difference apart from the speed it operates graphics and commands and the fact the battery lasts longer.
Why?
Well it's the same reason it's taking Sony Ericsson to bring us an updated OS.
There was lots of things ver1.6 cant do that ver2.1 can but as Android is open source and the fact 1.6 was really open to tweaking and the fact SE planned their interface around 1.6 before 2.1 was stable and released, SE went to town rewriting ver1.6 for the X10. The funny thing is most X10 owners have not realised this fact and keep banging on about wanting 2.1 on the update! Why? The X10 on ver1.6 does almost everything ver2.1 does we should all be asking for ver2.2 or ver3 from SE not 2.1
I cant be bothered to go looking for it now but there are huge similarity's between the X10's version of 1.6 and vanilla 2.1, SE tweaked it so much to give us a lot of fetures that 2.1 has on 1.6 as that is what they wrote timescape and mediascape but to be fair, I have never used them since the 1st week I got the phone but at least they did go to the effort of trying to give us the latest features that ver2.1 has but play a game like monkey kick on the X10 and a phone with ver2.1 really shows up the speed difference.
I have since rooted and waiting for a nice 2.2 rom to be released for my rooted phone.