The rack has been in the garage for a while now, and I owe it an honest review rather than the smug photo I posted when it first went in. The good news first: a proper rack genuinely fixed the cabling nightmare. Everything's on rails, the patch panel means I can trace a cable without unplugging three others by accident, and the PDU at the bottom lets me power-cycle a wedged box from one switch instead of crawling around behind it.
The regrets are mostly physical, and mostly obvious in hindsight. The garage has no heating, so on a cold morning the drives spin up reluctant and the metal sweats when the temperature swings. I should have either insulated properly or accepted this lives in a cupboard indoors and dealt with the noise. The noise, incidentally, is the other thing: 1U servers have small, angry fans, and second-hand kit comes with no concept of "quiet". You don't notice through a closed garage door, but you notice the electricity bill.
Would I do it again? Yes, but smaller. Half of what's racked could run on two low-power boxes that sip electricity and don't sound like a hairdryer. The rack scratched an itch, and that's a perfectly valid reason to do something, as long as you're honest that it was the itch and not the requirement doing the buying.