E60 more complicated / less reliable than E90?

[IamFODI]

I've had an E90 M3 for 6 years now, so I'm familiar(-ish) with that platform. Never owned an E60 but considering buying one in the next several months (assuming I can even find a RWD 6MT N52 car), so I'm trying to educate myself.

One thing I keep reading is that the E60 tends to be more complicated / less reliable / more prone to electrical issues than the E90. Is this true? If so, how?

Let's say I'm comparing a 2010 E60 528i and a 2010 E90 328i, as close to equal in spec as possible:

Both N52
Both 6MT
Both RWD

Is the E60 still more complicated? In what way(s)? Are there differences in electricals or construction, even in the same model year and similarly equipped?

Or does this "E60 is less reliable" idea mainly come from the fact that it's slightly older than the E90, had more standard equipment, and sometimes came with those finicky V8s?