Exactly. I have also found some recipes (particularly the period of his 15/30 minute meals) lacked flavour over style.
I don't know about the 30 min ones but I have found the opposite with the 15 min ones, because there isn't time to get flavour from slow cooking, there's a lot of flavour going on from other things - preserved lemons, allspice, etc.
Dh finds Jamie's recipes very hard to follow and says he can't work out what he is supposed to be doing when, but I find them much easier than other recipes, so it must be a way of thinking
My absolute favourite Jamie recipes are all from the 15 min book (but I ignore some of the things he has done to make them quicker to cook, like attacking chicken breasts with a rolling pin to make them flat -I just cook them in the oven as usual.
I regularly make the white fish tagine with couscous, preserved lemons, olives etc
The gorgeous greek chicken - also with couscous
The Asian fish and noodles in a miso broth
I also still use his recipes for pasta puttenesca and pea and prawn risotto from the Naked Chef