I read those reviews, and I work full time, but I decided to go with a styrofoam one anyway. It was terrible to adjust the temp through the first hatch- temps up, down, all around. I was checking it before I left for work, as soon as I got home and at least 5 times before bed trying to get it to stabilize.
Turns out, it was user error nearly 100%. I moved the location of the incubator to an enclosed space that was more temperature controlled and it has held perfect temp since Day 1 of my second hatch, which is currently ongoing.
So if you want a styrofoam bator, make sure you have a place to put it that is not in direct sunlight, gets no drafts, and does not otherwise change temps throughout the day. Get it up to temp and holding steady before putting in eggs (you'll have to do minor adjustments in the first couple days, the eggs change the temp- starting on a weekend is best). You'll be FINE to leave it there and alone for work.
EDIT: I have to agree with the above: Invest in an auto turner. If you think oh, I can turn the eggs 3+ times a day like needed but I did this for about a day before I decided I would never do that again. You wildly flux the temp in the bator opening it to turn the eggs, the eggs are hard to keep stable on the grates, you never turn them as 100% accurately as a turner, and the turner will turn them more times than you will probably have patience for. It lets you leave the top closed for longer periods of time, maintaining humidity as well. Soooooo worth buying.