Yes some of the desserts in Marks are very good. In the early days after rads pannecotte from there was successful. Although now I have to avoid the calories and cannot smother everything with double cream or even single cream as I used to.
I think the whole thing relates to people contantly experimenting and trying new foods, but maybe leaving a few weeks before trying a food item again. I agree the creme caramel will be easy for many people to get down.
You say Rosie you loved swiss roll. Well I regularly but Marks fresh cream chocloate roulade and find it goes down well as does the one by Morrisons. Try to find one that has along date so its softer. After 1 or 2 slices I slice and freeze the rest. Of course fluid is still essential.