I, also, could not abide the Wren advert, with some woman shouting at me. For that reason alone, I did not even look at their products! Because they had a discount last year, we went with Wickes. The kitchen looks good and the service and the fitters were absolutely fine.
I don't know if this information is correct but I was told by an independent tradesman that Howdens have two levels of quality. The higher standard is sold direct to the customer but the lower standard is used by builders, which is why there can be shoddy products in new builds. Worth checking out but do be aware.