Alex Moulton is a suspension engineer who designed systems for the Mini car. He is radical, but not nuts.
His bikes have a cult following and are highly respected, and he was building dual suspension bikes when the MTB originators were riding tricycles. In my small town there are 2 Moulton users.

He uses a space-frame construction which is very light and stiff. They dont fold down, but do split in half for transportation.
They are effective racing and time trial bikes , excellent touring bikes, even for tough expedition style riding and make excellent commuting and utility bikes, with a good load-carrying ability. The suspension system is well proven and very reliable.