Why do you hate bifolds out of interest?
For me, as most of my design work is scotland based, bi-folds have a number of draw backs.
If they are external opening they catch the wind when open, with sliders you can crack the door open a little to give ventilation but with no danger of it catching the wind.
Or if they are internal opening they need a lot of clear floor space - with sliders you can have furniture right to the edge of your space for the 99% of the year the doors are closed.
The frame to glass ratio on bi-folds is significantly higher than large sliders, so you end up looking at frames rather than having a large expanse of glass (which goes back to how often they are likely to be fully open)
Cheaper bi-folds tend to need adjusted when the weather changes, or tracks get jammed up and the expensive ones are just that, expensive - there are a huge number of moving parts to get these things working and no body does the proper maintenance
With a 4m opening I've actually done a massive fixed panel and just an opening door at one side, it was cheaper than bi-folds and made the space work better as the fixed door position meant the furniture was easy to place in a relatively small addition.
The other thing is, they are no more practical than a standard door/sliding door etc so they will fall out of fashion soon enough...