Its like writing in all caps: the message is the same, but the presentation makes it sound different.
At least for me, a string of posts all by the one person comes across like one of those people who like to tell those breathless stories wheretheydidthis *gasp* andthentheywentanddidthat *gasp* andthentheydidtheotherthing *gasp* anditwasreallyinteresting.
Its stop start stop start... When multiple people are posting it makes sense that things stop and start, because its a conversation. When its just one person posting, its like talking to yourself