mmmm... Living the UK I dont have any great examples, the best I could do just now was this, the yale on the left is euro.
I'm not really saying that picking euro locks with regular (non-slimline) picks is impossible, it is just that they seem a little clumsier in the lock, the slimlines are easier to manoeuvre in tight keyways.
Take a look at this for example. I've tried to show a really tight keyway on a pretty nice yale padlock with a selection of picks. From left to right, A ultra slim diamond I made, a slimline diamond, a large slimline diamond and a small regular diamond.
I made my small diamond almost specifically for this lock but you might be able to see from the picture that the large and regular sized diamonds are going to struggle in this keyway, especially considering you have to get a tension wrench in there as well. (I use top tension for this one most of the time).
Lets look at those picks in a bit more detail:
If you take a look at the regular diamond on the far right, you can see that the tip only extends half again as the shaft is thick (if that) where as on the slimline version (second from the left) the tip extends to the height of the shaft again. With the regular pick it will be hard to lift a short pin behind a long pin without disturbing it, just making it a little more clumsy. I've not found a use for the large diamond as yet so ignore that but it does show a tip extending more than twice the width of the shaft.
Picking with slimlines from the off-set will put you in good stead to practice picking properly, you just have to be a little more careful not to be heavy handed with them because whilst they are strong, they do not have the same "pry bar" strength as the regular ones.
You should be being very deliberate and gentle with the picks anyway, especially in a new lock, hardly any force should be required for tension and to get the pins to set.
Hope that helps, apologies for the blurry pics, it's late and I only have a phone to take them on.
