I’ve not used the new
GW stuff, but am quite happy with my KR.

1,850 of Eldar in 2 KRU worth of foam.
The Eldar tanks actually pack pretty tight. You can fit a good number of them into a KRU worth of foam. Assuming you left the turrets off. I put some of the extra bits and bobs on my Fire Prism, so needed to widen the back of its tray. Not hard to do with a sharp knife.