I've finally seen this movie, on Isle of Wight last weekend.
My impressions:
Jake and Anne are great. Good chemistry between them, good acting. As for reminders of BBM I was reminded of Lureen exactly two times, one when Anne's character was on the phone, and once I heard Lureen's voice when Anne said something I've now forgotten. And there was one or two moments where I briefly saw Jack Twist in one of Jake's facial expressions. Other than that, it was hard to connect the two actors with BBM, I think.
The story is crap. Very predictable, very shallow, very Hollywood.
The viewing was very enjoyable, since my co-viewers all are hardcore Jakeaholics, and there was a lot of stopping the movie and going back and forth in slow motion while commenting on and drooling over various Gyllenhaalic undressed body parts....