I suppose I qualify as a purist. Not a hardcore purist, but I do generally prefer the manga over the anime if it came first. For me it's much the same as reading the book a movie was based on. You're seeing the author's intent/ideas far more directly than a movie usually does it.
When it comes to translations, I tend to use names in priority of Creator's Known Intent (Luffy/ Jango/Zoro) > Officially given US name (Belle-mere, Klahadore) > Most logical sounding names (Ener, Lucci, Paulie).
However, I'm willing to accept drastically different names IF its in the name of comedy (i.e. it's intent is to retain a joke or pun that wouldn't translate over properly). Lacking better examples off the top of the head and since Dr. Slump was mentioned, I'll use the example of a chapter featuring a vampire parody called the Trampire (wants money, then blood, in that order. Just picture Nami as a Creature of the Night). I highly doubt that was the original name, but if the original name followed a similar kind of pun then it's fine in my mind.
I can even accept it in the name of mild censorship (I suppose "Super Punch" while I agree its silly, can serve as an example here), but only if its for something that would potentially prevent publication in the US in the first place.
Something completely baseless and pointless though, such as the Viz Dragon Ball calling Sergeant Metallic of th Red Ribobn Army by the name "Full Metal Jacket", is just unacceptable to me.
But it's all jus tmy opinion. I could be wrong.