But ICs are a lot more 'brittle', having little tolerance for sudden power spikes.
You guessed it, I fried four microcontrollers by trying to get these wallwarts working with my circuits. Not too happy about that: at EUR 3.50 a piece, it adds up quickly.
There are ways to stabilise the power lines, but the ICs that do that effect a voltage drop: you need 9V if you want a stabilised 5V circuit. And stabilising a 5V input will yield only a stable 2V -- too little to drive LEDs in any meaningful way.
I guess I will need to invest in a few 9V/400mA wallwarts, and get a few stabilisers and the appropriate condensators. Those parts cost only just over 50 eurocents per set, which is good. I do want to present the recipients of my electronics projects with the appropriate wallwart to go with it -- and including the stabilisation circuitry would allow me to invest less in wallwarts and more in the actual electronics themselves.
Also, I would dearly love to support my local electronics store, but charging EUR 1.10 for a 2200uF/16V elco when I can get the same for 26 cents from my usual online store sure isn't helping.