There is no doubt that Steven Osborne has all the technique required to deliver all that Debussy requires of his pianists on paper.
These are meticulously crafted gems where the impression is that everything has been thought through with the greatest care and finally presented glittering with polished perfection. The recording from 2006 is admirable too in presenting this with impressive fidelity.
So far so good and for many this will be more than enough and rather more than might be expected yet there is just that Gallic coolness, a possible holding back of emotion, that I don't sense in the best of alternatives. Three recent alternatives may serve to illustrate what I suspect to be the case - and please note my reluctance to be too forthright over this, possibly contentious, point.
The much admired and award winning set by Krystian Zimerman is certainly one of the finest currently available and he brings a far more aggressive approach to these works. There is technical perfection here to be sure and, additionally, there is a passion missing in Osborne's account. I can also agree that for some there is too much passion here and not enough of that Gallic reserve.
There is more reserve in the account of Thibaudet, who as a Frenchman, probably has a more intimate understanding of Gallic reserve. He too, has plenty of technique at his command but eschews the open emotion and bravura of Zimerman preferring a cooler approach altogether. Some have found him too cool, even emotionally detached, but not in my opinion, more so than Osborne.
My last example is that of another young Frenchman, Jean-Efflam Bavouzet who has also been the recipient of much praise and awards for his complete Debussy. Here we have a definitely warmer approach than that offered by both Osborne and Thibaudet but without the aggressiveness of Zimerman.
All of these individually very fine players have received golden opinion for their Debussy preludes but they are really very different. I would suggest that in terms of warmth and coolness and ordering them in order of hot to cool I would place Zimerman as the hottest, Bavouzet as the warmest followed by Thibaudet with Osborne being the coolest of the four. This is not a value judgement in any way, just an attempt to give an objective comparison to aid choice.
So, bearing in mind the perceived variations as described above, for those who like their Debussy on the cool side I would suggest that Osborne should be a serious consideration along with Thibaudet. For those who like their Debussy hot, go for Zimerman and for those who like a certain warmth with their Debussy it may be that Bavouzet would be the best choice. All are very fine in their different ways and all are blessed with recordings that exactly match their interpretive style