I was thinking the same thing about the modeling light. I currently have a rovelight with a 7 watt led modeling. If its in a double baffled softbox, the modeling light is so dim its barely usable. Was hoping the AD600 with its 10 watts would be somewhat acceptable for studio work because I will use my lights for about 30% studio and 70% location.
It may be best to get the following:
Newly anounced - GODOX GT600IIM (for studio key)
GODOX AD600B TTL for location / studio fill
The GODOX GT600IIM specs appear to be the godox competition to the Buff Einstein except the Einstein has the Godox beat with the 250 watt modeling compared to the 150 watts for the Godox.