Assuming for the moment that this is a move by the Russian government. I think this is on the whole a bad move by Russia. There's some successful intimidation but it also is going to piss people off. It also sounds like Estonia is weathering it. But the real net gain is for Nato. We're getting a chance to play defense on cyber-warfare when nothing is on the line militarily. Presumably Russia isn't using all their best stuff, but it still represents a value source of both practice and knowledge. We're going to be better prepared next time.
Also, props to Estonia. They seemed to react quickly and in smart ways. I hope Nato will help them with repairs. I don't think any large scale retaliation would be a good idea, but they are our ally and they deserve some aid.