well, i'd advice you to take the one with the best website, and the best face to outside, if they are professional you should go to them,
then 1.2€ per slot is way too much, every of those 3 got probably linux. in the end its your choice also for the location, germany and the netherlands got both good pings as i know.
(normally 50ct per PRIVATE slot)
i know e.g. wolfa-hosting, its cheap but i think they arent a big company, so your choice how you wanna decide