(BAD Point)
V8 only supports AutoCAD files that have native fonts and native linetypes. If you have files made from AutoCAD with some add-on packages that have their unique\ custom linestyle, V8 will not display this correctly. Bentley doesn't advertise this loudly. In fact, most office use some sort of add-on product to AutoCAD. So beware with the AutoCAD you modify, you could corrupt certain elements or you could be getting proxy elements you can't modify at all.
(This is a GOOD point) As for the MicroStation side... V8 brings a lot of enhanced features it copied from AutoCAD to accomodate many of the features/ elements from AutoCAD.
BAD POINTS!
You can only use AutoCAD commands while in V8 ... IF YOU WISH to maintain the AutoCAd file. The second you use a V8 MicroStation command it becomes a MicroStation file. Therefore you need to do a saveas/ translation to AutoCAD which contradicts the use of V8.
Also V8 files can't be read by MicroStation J or earlier. You must do a saveas/ translation to a lower release.
And the Bentley sales people will claim V8 does all these web/ FTP new things without telling you that these are added products to MicroStation and services\ subscriptions which are additional costs to V8.