whats up with the diff?
burst.ninja shows a estimate of 29pb and burstcoin.eu of 17pb.
the basetarget is for several blocks below 700000 which only happend a couple of times until now.
looks like some huge miner joined the game

aehem, no: burst.ninja has a very short interval for calculating the diff,
it may just show the raw value (translated to Petabytes).
burstcoin.eu has a sliding day-average, hence the difference.
If you look at a day-average, the last week looks like this [PB]:
14.0352
11.8937
12.3512
11.1807
13.4713
14.4589
13.5746
If I look at the last 7 raw block values you just see the diff-regulation busy at work [PB]:
18.4393
20.8804
21.5826
21.2423
20.7699
22.8331
23.2555
but these raw values are "useless", you need to average (to your liking) - just like
burstcoin.eu does.