Funnily enough, I test drove a 135i in Jan the year when I started the new car search. My god it was fast and made a stunning noise, but other than that it left me a bit cold.
For the times when you can use the power, I'm sure there's little else (if anything) in its price bracket to touch it, but (personally), I found the interior boring although very well screwed together and the seats though supportive, quite hard.
Ultimately for me it's biggest floor (in hatchback guise), was the looks. No matter which angle I viewed it from, it just didn't do anything for me and actually bordered on ugly. The coupe version was much prettier, but to be honest is effectively a 2 seater as the rear legroom is non existent. I know we buy cars with our heads as well as our hearts, but I just thought when the power giggles had worn off, the fuel bills and insurance mounted, I would still be left with a car that had a super engine and drivetrain, but a car that looks wise I just didn't connect with, if you know what I mean.