The reason this other power supply is so cheap compared to the Diago is quite likely that Diago designed it, subcontracted a factory to build it, and said factory built a couple on the side too... It happens.
Either the diago supply is essentially a 1spot/daisy chain design. I'm very happy with my 1spot, never had any issues or noises and I've powered some big boards with it. Now I downsized and sold everything else though...

There's JUST enough space left for the Digitech DL8 delay I have in the mail. Then the danelectro overdrive will be replaced by a TIM so I'll have to sacrifice the Bad Monkey me thinks.
This pedalboard is the result of a LOT of trials... I've had in the past three years:
2x Bad Monkey
Danelectro Metal I (still on)
Danelectro Vibe (still on, modded)
Danelectro Transparent Overdrive (still on, to be replaced by TIM)
Danelectro Fuzz (gone)
EH Small Stone (gone)
EH Russian Muff (swapped for Little Big Muff)
Subdecay Blackstar distortion (gone)
Subdecay Stupid Box 2.0 (gone)
Seymour Duncan Power Grid distortion (gone)
AMT P1 (gone)
AMT DistStation (gone)
MI Audio Blues Pro (gone)
MI Audio BoostNBuff (gone)
MI Audio Crunchbox (gone)
Self built Crunchbox (still here)
Self built BSIABII (gone)
Carl Martin Surf Trem (still here)
Carl Martin Plexitone prototype (still there)
Carl Martin ACTone prototype (still here, modded)
Carl Martin HotdriveandBoost (still here, modded)
2x boss SD1 (both modded with my own sets of mods, one sold to a guitar shop, one given away)
2x boss DS1 (one sold to a guitar shop, one I still have, best set of mods I ever did)
Visual Sound Route 66 (gone, that was a great pedal)
Danelectro Danecho (gone)
TIM (gone, very missed)
I incidentally kept most of the cheaper and pro pedals I own, and sold the 'boutique' ones. I really do miss the TIM though. And the Boost N Buff would come in handy right now to replace the Bad Monkey as it had a great buffer.