East Dulwich Grove is definitely not healthy at 9:00am....standing traffic all the way up to the crossroads with the Village. Awful for cyclists, school children, pedestrians and I imagine car users. Standing traffic, fumes and pollution.
It'll take a month or so to bed in and for any changes in traffic patterns / flow / volume to settle down. Not much point in looking at it after <24hrs in place.
@slartib is right, they should have done the whole Healthy Streets thing at the same time while traffic is relatively light. I appreciate that timed restrictions are difficult without camera controlled junctions which you can't put in at short notice but the principle of the HS is difficult to assess when you close one junction.
However - it's in now, people will (gradually) adapt and in 6 months time a proper assessment can be done.