I think it's all valuable, since it wasn't put through the usual political screening before being written; other than his own, of course.
What caught my ear was when the French officers inquired about if Sir Sidney had placed any of his crew inside Acre, since they had noticed a distinct improvement in gun fire effect; which is some confirmation of the significant effect of British gunnery. This was stated clearly by Smith in his reports but from the French side about the only thing, that I can otherwise find is N's boast about Smith only supplying him ammo which his soldiers received 5 sous payment for and went about their work laughing. Which I think may have been just another Napoleonic con-job. Last thing in the world that N would want to do is make a report concerning Sir Sidney's devastating cannon and carronade fire that stopped him. So, make a joke about it. Seems to have worked for the most part. However, it should be noted that N is well known to have demanded production of a French carronade and, as far as I can tell, the only first-hand experience N ever had of the effects of British carronade fire was at Acre.
The mission that Tillery was on is covered in other texts, of course, and for the most part they line up with this text. One difference is in Shankland "Beware of Heroes" it's stated that a prisoner exchange took place shortly afterwards and even names two Frenchmen who were returned, but, as we know, the exchange, at least for Tillery and his men, did not happen for some 6 months.