I've quite an opposite experience regarding F30. While my E90 was in the shop for SRC mixer recall & software reset, my dealer provided F30 328i loaner for 9 days. Firstly, I've to say BMW really does an excellent job on F30's suspension especially when driving on city streets & cruising around town. In fact, that's my favorite memory of F30. However, I still prefer E90's suspension when cruising on interstate highways. E90 provides firmer ride & more feedback.
Now, my least favorite feature of F30 is its steering. Again, I'm not here to re-start the flame. I am simply saying that steering can be "light" & "heavy", the most important job of steering unit (in my opinion) is to provide additional feedback. There is no dispute, F30's EPS unit is on the lighter side whereas E90's HPS has a heavy feel to it. My problem with F30's EPS is not really about the "lightness" , rather it is about the numbness. The best I can describe this sensation is like letting a blind man driving an E90 and he will be able to tell which side of the wheel is running over the uneven surface or potholes. On the other hand, it will make it much difficult for him to differentiate such sensation while driving F30.
Before F30 fanboys start chastising me, please comprehend I have nothing against heavy or light steering. I do have problem with numb steering especially that's the reason I order a BMW and not Lexus. If BMW is going down the road to make EPS unit default on most vehicles, please make an effort to improve liveliness. Due to the nature of EPS design versus HPS, it is very difficult to duplicate "hydrualic damping" effect. It is not entirely impossible because I recently test drove 2013 Boxster & Porsche nails it right. That's some well-designed EPS unit. Although it feels lighter than E90's HPS, it is lively and no numbness. I dream of such an unit in upcoming M3.
The saving in fuel consumption isn't much in reality when HPS is replaced by EPS. BMW is smart to not muddy the waters when they introduce F10 M5 + F12/13 M6. They went back to HPS unit for M cars even thought EPS are readily available.
Just my 2 cents.