I have both the regular Sidewinder and the Huben K1 in .22 caliber. I can't comment on the relative noise between either the mini and the standard, nor the .30 standard and the .22 standard, but the difference between my two guns in terms of noise is huge.
Have you shot the Sidewinder? It is a fine gun, but is much louder than the Huben even at lower power levels, and the Huben has a much better trigger. Add an LDC on a Huben and there is no comparison . . . the Sidewinder is louder even at lower power levels. If noise level is important, the difference can't be overstated. And as a note, I find the Huben without an LDC is a good bit louder than a Marauder (without an LDC) at equal power; adding the LDC makes them about equal to my ear.
One thing to clear up - although the Sidewinder barrel is threaded, it is not a 1/2-20 thread so common LDCs wont attach directly to it (I think it is 13 x 1mm metric but am not sure) - it is so close, but not the same which is very frustrating. You will need the AoA adapter to replace the factory "moderator" with an aftermarket one, and you will definitely want to replace the factory moderator if you need to get the noise down. I'm running a Huma 40 Standard on mine, but it still is loud, in part because the action is so loud - much louder than the Huben action.
Another thing - while the gun is quieter when I dial down the power, on mine the accuracy degrades as the speed drops. I have heard this from other people as well - don't know why as the ES is tight even down in the 700's, but the accuracy is much worse, and it starts to get worse below about 875 or so and builds from there.
If you do go with the mini, you might want to read this great thread on quieting it down:
https://www.airgunnation.com/threads/hushing-the-sidewinder-mini-30.1307559/