I gave the EA version a regular wearing today (1 spray to chest). It's probably strong enough for me, but I won't go to two sprays because I find that this kind of frag can nauseate me. I think it's the combination of patchouli, amber, and wood, especially cedar. Here, there is sandalwood and cedar listed as notes, but they must be very mild, because I barely detect anything resembling wood and this frag doesn't bother me too much. There is also the possibility that it's too blended, because the new Givenchy Gentleman doesn't seem to bother me. GG has better note separation, so right now I'd guess it's the blending that is most likely to blame.
Anyway, Giorgio for Men does seem strong enough, but I could certainly imagine it being stronger. It has a bit of that "synthetic"/rubbery amber thing going that's common in many older frags, but it's not too bad. This is not really the kind of frag I enjoy most these days, but it does seem to be at least a decent formulation, unlike some others I've encountered. In other words, if there's too much blending of certain notes, an accord results that some people find nauseating.