I can briefly explain about Engineering for this 3 companys briefly after seeing their website.
3393 produce meters for different industries. I think the meter is not high tech product. For energy/electricity management, those big companys such as ABB/Allen Bradley/Schenider/Seimens/Honeywell are the professional and more reliable.
1685 only do high voltage (maybe 6600V) and low voltage (380V/220V) distribution by distribution switchborad (so-call switchgear/ DB and related safety control element circuit breaker, fuse etc.) The management system is doing computer programming (nothing special) to monitor the system status by to feedback signal from on site instruments.
The software should be good in quality and user friendly and popular. "Popular" is important because the end user can employ some IT guys to maintain the system. So I will use common system seen in HK are ABB/Allen Bradley/Schenider/Seimens.
In china market, I am sorry that I am not familiar with.