Yeh, whats the deal with broad strokes?
Mainly because everyone has different expectations. Putting a few posters up with "koreptycje" isn't going to get you much, but getting a very well connected client can see your phone ringing constantly. Likewise with the working hours - split shifts can really drag you down in winter - but if you like a sleep in the afternoon, they're a pleasure. Same with the cost of living - sure, you can shell out 25zl for a glass of JD and coke, or you can pay 10zl and drink the local alternative that tastes exactly the same anyway.
I'd say Poland is very much exactly what you make of it - you can work 20 hours a week and have a pretty easy life, or you can work 40+ hours a week, half kill yourself and make a fortune.
Though the work is more demanding and senior managers (you are not the first or even the fifth native speaker teacher some of them have had) don't usually want 25 year olds. Unless they're pretty or charismatic or exceptionally good at teaching. Ideally all three.
The big issue with corporate clients is that (in my experience) - if you get them through a school, what the school (and HR) expects versus what the client expects are often two totally different things. I've lost count of the amount of times that I've been told "here are the objectives" - only to discover that the student actually thinks that the objectives and course book are rubbish and not worth bothering with.