e60s - any good?

Bit of a general query I know.

I like my BMWs and my daily is a late e46 330 sport touring manual. Nice car but 160k miles and rust is coming through on the rear arches and I just cannot be bothered with the grief on a daily.

I have considered e39s but they are just as old and rust prone.

I've never been particularly excited by e60s but the tourings look quite nice especially in sport spec. I gather they are not as well built as the "golden age" of e39s, but at least they don't bloody rust (or do they?)

Had a quick look on autotrader and there seem to be quite a few larger engined (530, 545, 550) with nice spec (lots of toys, head up display, pan roof, etc.) for £4-7k, but mostly 150k+ miles. Is something like this going to be a huge world of pain and waiting for a large bill? I don't want to swap rusty arches for expensive electronic boxes...

Or am I better of looking at e91 tourers? Happy to go with an auto box as it is a daily but I am worried about reliability...