I think if Wulf says "adjust in your head, at the table", he means something like add +2 to attack, ~20 hit points and +1 to saves.
Not actually working out the precise details according to the system.
And I think that's the entire point against the 3E system - sure, I can just ignore the rules, but ignoring is not using, or even benefiting from the rules.
Well, I hate using the evil number 4 here, but that's exactly what 4E makes the rule. Which I personally find way more comfortable. Especially because I know that I didn't miss anything important (like that an NPC would have better gear now, more spells or feats for the monster, ability score increase... Sure, each individual might seem inconsequential, but these errors stack...)
So, somehow the fact that 4E codifies a rule that many of us have already been using with 3E is a point against 3E?
Strangely, from the way you are afraid of missing anything "important" - as if a +1 or +2 here or there would matter that much - you seem more rooted in the "everything must be like the rules say", and only able to start fudging and adhocing if the rules tell you it's ok.
Psst, it's ok to fudge and guess and adhoc in 3E too. The books evne say so, even though in smaller letters than in 4E.