Guild Wars 2

What level, what fractal and where do you stack?

I got four shards in a day just doing the tier 4 dailies, I suspect the drop rate has been increased a bit.

I tried doing a lvl 30 mob clearing and a lvl 28 grawl killing spree but instead of ending up with shards I kept ending up with vials for some reason. According to the game itself and to the wiki shards now drop at 21+ can anyone confirm that?

They do, but at this level you can still get globs or vials instead (and with a far better chance). Better try levels above 50.