[ezmaass]

It's really a matter of which engine you want - I6 or V8. The 535 is plenty powerful. The 550 is MORE powerful, obviously, but not usable most of the time. If all else was equal, and you enjoy power, get the 550. But do keep in mind, all else is usually NOT equal.

The 550 will cost more to maintain long-term after CPO, warranty, etc is long gone... assuming you keep it that long. Inline 6's are BMW's bread and butter, and the N55 is a strong engine. The N63 in the older 550's is clearly a bit of a problem child. If you already had one, fine - but I'm not sure I'd tell anyone to knowingly buy one at this point, care package or not.

Given you're looking for a manual, you're at a huge disadvantage with choice. They're rare. And given how many options there are to choose from on the 5 series, I'd just lay out your priorities.

#1 - Manual Transmission
#2 - X Package
#3 - Y Package
#4 - Z Color(s) Exterior / Interior
.
.
.
#n - X Engine

As insinuated above, I'd probably put the engine option of choice lower on the list since it'll probably have much lesser influence on your daily enjoyment of the car over the transmission type, packages, and overall aesthetics (colors, trim line, etc).