Think we can only be a bit more patient from this point on wards as the 710s seem to finally have a functioning software (fingers cross) and they can build up enough mileage without another breakdown.
As for the 172s departing before the 710s start that was pretty obvious from the start the way Bombardier been conducting their software. It's just a shame TFL didn't take the user group's advice sooner in deploying some 378s. Personally if it were me I would pull one more from NLL, WDCL, & ELL each to make a proper six unit service. Doesn't matter if other services suffer from some delays in the meantime (5% loss!) it's only a temporary measure till the new trains come into service.
Anyways I hear theres some more runs and testings with the 710s on the Goblin, is this just for driver familiarization training and WCML is being used for mileage accumulation or a combo of both purposes just to cut in some time?