bifold doors - good idea or bad?

[JumpJockey]

The place we're moving to has cheap and grotty french windows, will need replacing anyway. Does a bifold door make that much difference to usability of opening? Is it annoying if you have to open the whole thing, where with a french window you could just open one side?

and did I see someone saying on here that they're actually incredibly naff?

We have one with a service door - it opens just like a normal door and the other side peels back - you can open it by as little or much as you like...probably is naff though