We have That's not my... dinosaur, monster, baby and this one - tractor. (The 'baby' one is the current favourite but moreso because it is a bit different because it has a mirror at the end). And we do love these books - honest - but it does seem already noticeable that some of the materials, fabrics and adjectives are repeated in the different books.
I would always recommend these books to anyone looking for a good book for their baby but I would also suggest that, if you already have some, check the pages 'in person' first if possible. I just think they will have a bit more longevity if each and every one is different - rather than recycled!
We do enjoy the tractor one but because it is not 'face' based, it doesn't command as much attention. I did think, seeing the first page that has sheep in the trailer, that the theme would have been carried through and farm animals included on each page to capture the imagination, but this isn't the case unfortunately. Maybe this is one that baby will be more interested in when he is a bit older and get in to diggers, lorries etc.? A nice addition to our bookcase - but not our book of choice at present.