Funnily enough I didnt always have such a bitter spit at Dawnguard for its new random events.

Sure now the vampire town atttacks were super impractical for Radiant AI to cope with but before that it showed promise.

Example being after a while doing the vampire storyline and travelling with Serena I was set upon by a band of Dawnguard in Dragon Bridge.

"Ah!" I thought "They took me in and gave me a crossbow only for me to turn traitor...now theyre hunting me down" and was quite pleased for it.

It did indeed give the story a bit of tangible vastness and some weight to my actions, I assumed that if i had stayed with the Dawnguard the situation would be flipped and it would be Vampires springing surprise attacks on me for turning Lord Harkon down...forum readings seemed to support this!

...I was wrong.

As it turned out the vampire attacks were unrelated to which side I chose and thats what made it an issue.

Had they started as a result of your actions it would have been fair enough but not some fresh faced former imperial chopping block tourist looking to scraqe enough gold together to buy an alchemy lab for their home...

What do you think?

Keep the Master Vamp & thrall raids as part of the vampires counter-attack against the forces of Dawnguard?

Only when the Dawnguard make their move?

did i understand it correctly you got attacked by Vampires while siding with the vampires or attacked by Dawnguard while siding with the Dawnguard guys??
and you think it is a good idea to keep it in?

sounds more like a bug to me or you must have really pissed them off
i only got attacked once by dawnguard while siding with them, but it was after i had beaten the crap out of Isran by accident during a vamp attack on fort Dawnguard
so everyone turned on me and so The Dawnguard was effectively teaming up with the vampires
it even went on inside the fort Dawnguard and Vampires attacking me and Serana but they lost
had to reload a save since they kept attacking me

You can also go to a different region and wait for 48 hours. After that, they should be back to normal hostility again. Also, I think the author was trying to say he doesn't like the vampire attacks after you join the vampire's side.

The vampires attack you because the vampires in lord harkons castle are constantly against each other and there are lots of groups vying for power of his throne, they hate you the most cos you happen to be the most successful one at being heir to vamp throne. Internal disputes but what can you do aye?

Vampire attacks happen regardless of your actions, whether you join Dawnguard or the vampires. They are completely unrelated to the questline, can happen as soon as you install Dawnguard and will continue to happen after you complete the Dawnguard questline.