I wear mostly Assos apparel and I own a pair of HaBu5 jackets which I have a fair amount of miles on. The previous review by MWS is spot on from my experience with the i.J.Habu5 jacket. You may want to consider a few more details about the HaBu5, considering it's a fairly expensive item...
The fit is typical Assos, "very" snug, body hugging and comfortable on the bike but not comfortable off the bike. The HaBu is designed and cut for a trim, fit athletic body type. It's definitely NOT a good choice if you have a less than trim, fit body and you will probably feel very uncomfortable wearing this jacket. This is not a casual, roomy, club fit jacket! Also, some cyclists may not like the rear pockets on this jacket because they are a bit unique...The side pockets are only zippered and they do not have traditional style slip-in open pockets. The center pocket is open but it's not very large. You can fit a lightweight pack-able wind/rain jacket (150g) in the center pocket, but it's tight. The sleeve openings are also designed to be close fitting to your wrist, as a result, they can be a struggle to fit your hands through when putting on or removing the jacket, especially if you have large hands.
Overall, I think the HaBu5 is a beautiful stylish looking piece with exceptional Assos quality. It's designed for temps in the 40's to low 60's. With a winter LS baselayer, I'm comfortable down to around 37 degrees with moderate winds. The front exposure is essentially windproof, the back fabric breaths very well and it's relatively light weight for a mid-winter jacket.
FYI; 5'8.5", 160lbs, 32" waist, 41" chest. Wear size L in HaBu.