I’m only a week into using this, but so far, so good.  I chose this frame for 4  reasons:
1) In changing over from using a boxspring to not, these wooden slats gaps are indeed a maximum of 3” apart and therefore supportive enough for my memory foam mattress.
2) I wanted ample under-bed clearance for storage and this allows 12” tall items easily.
3) If there were any support-legs on the sides of the bed, aside from the corners, I would inevitably smash my feet into them.  This has those toe-stubbers safely under the middle of the bed instead.
4) The width of this frame does not exceed the width of my mattress.  I hate when I swing my legs down to get out of bed and my calves hit a frame instead of a soft lovely mattress.

This is meeting all my goals so far.  Additionally, there has been no squeaking, assembly was intuitive and instructions are easily shown.  Everything was packaged well and I have the option to later attach a headboard (and I think footboard as well) if I so choose.