>>6230750I have both in my house and I like them for different reasons.
Personally I think the BILLY looks a bit classier than the detolf. But maybe thats because as collectors we've seen the detolf used excessively. I like that the detolf has more glass sides which in turn lets in more light. You might want to invest in a lighting set up for a BILLY since it can get a bit dim in there. A pro to the lack of light in the BILLY however, is that I dont worry about UV damage as much since it shields out a lot of natural light. My house that I live in doesnt accumulate too much dust, I think dust levels vary from region to region. But I have to say the glass door has done an excellent job with keeping dust basically non-existent in there.
You can also switch out the handle of the shelf to any hardware you want which can add a bit more style. They just give you a dinky little wooden knob thing. I think a black shelf with a metal knob would be a good combo.
Now Im not sure if this will pertain to the larger BILLY bookcase but the narrow one I have I would say is arguably less sturdy than the detolf. Its height plus the fact that it doesnt have much surface space to balance itself, makes it really easy to tip over. It gets even worse when you install the door because of the added weight to the front. I was really worried about it tipping over so I did install the bracket that attaches to wall to make it secure. This may not be as bad for the bigger BILLY, but again I would watch out when installing the door because it does add quite a bit of uneven weight to the shelf. But ofc you can correct this by installing the bracket IKEA provides you. Another bonus of the BILLY is that you can arrange and space the shelves however you please. but detolf you only get the pre-set spacing of the shelves.
Sorry this was so long but I hope it was helpful! If you have any other questions I'd be happy to answer.
>not my pic, just a BILLY set up from MFC 