It really depends on country. In germany there is a note on each chart that the 250 below 10.000 does not apply to class C airspace, which is placed around any somewhat bigger airport. So you actually have to check the AIP of every country you operate in and be aware of the differences or just (its much easier) use 250 below 10.000 anyway. By the way, even in the UK i was told by ATC to keep 300 kts minimum well below 10.000, and personally i do not like that at all since the birdstrike risk goes up a lot below that altitude, not to mention that the classic windows were only tested up to 280kts.