My Mrs is Slovak and I've been travelling over to Eastern Europe constantly for the past 10+ years. I've driven in Poland, Austria, Slovakia plus all the other European countries (Germany, France, Italy etc). Main thing to be aware of are how crazy the drivers are - they take far more risks than people in the UK and the phrase "Anything Goes" is fairly appropriate. The condition of the roads has generally improved with more motorways but if they are bad, then they are really bad - e.g. your entire car almost vanishes into a pot (crater) hole. Don't bother with speeding as they will get you and the Police are not really the forgiving kind with Mafia widespread in the region.
I would personally use the Galaxy as you will be less inclined to speed and you can carry more gear. Saying that, when I was last over there in August last year, I spotted a FL Golf R 7.5 in the local town! Don't forget to drive on the right and have your main headlights on as well. Plus if going between October - April it's law that you need winter tyres fitted.