SRD said:
While blinking, you take only half damage from area attacks (but full damage from those that extend onto the Ethereal Plane). You strike as an invisible creature (with a +2 bonus on attack rolls), denying your target any Dexterity bonus to AC.
You take only half damage from falling, since you fall only while you are material.
This sentence was the problem. Earlier in the description they say that the Blindfight feat does not help against it since you're (at least part of the time) not only invisible, you're gone. Later though this sentence says, you're treated as an invisible creature
for your attacks. So on the one hand you could argue that things like Blindfight do not help the attacked person to retain it's Dex bonus... thus being sneakattackable... while on the same time you have a miss chance that's compared with concealment in another part of the text... while on the other hand you attack as an invisible creature, which would mean that any tactics that thwart invisible attackers should be valid.
So IMHO it's up to your interpretation. I stick with my gut feeling that says: You have two effects on you.
A) you change the planes. This imposes Factor 1, a miss chance because you're not there. Naturally, this has nothing to do with invisibility.
B) you're effectively invisible, you see the opponents, they don't see you part of the time. This is Factor 2. Against this, IMC, Blindfight would help.
In case both factors apply to your target (it does not see invisible creatures and is not able to strike ethereal creatures), 50% miss chance apply. In case one factor applies, 20% miss chance apply.