I purchased a queen-sized, metal bed frame with a decorative middle support to see if I liked it before buying another.  It was and has been great so far (1 month in).  I was able to assemble the frame by myself easily.  It was solid with no wiggle in any of the slats that slide into place with a notch and then lock into place with a plastic clip so they don't pop out.  Of the two beds, only one screw was wonky, but they include a spare of each part that worked.  While I don't jump on the bed (these days), my two 25-lbs. dogs do.  The bed has never squeaked.  

The storage space under the bed is GREAT!  It doesn't fit my extra large, hard-sided suitcase, but it does fit my extra large soft-sided suitcases.  It also fits my shoe-sized plastic containers stacked on top of each other.  I have the long type, so they slide completely through with no bed legs obstructing them when I pull them out from the side.   The slats don't bend, so nothing gets crushed.