What is the warranty on the fuel pump now, like 10 years or something? I wouldn't be as worried about that as I would the durability and cost to repair the turbo(s) down the road if you plan on owning for a long time. I do think the n52 in the 328 would be more reliable/cheaper long term, but it has it's issues as well. Here is one for example:
Metallic Ticking noise coming from engine? - BMW 3-Series (E90 E92) Forum - E90Post.com