If I had the choice between a Skywatcher ED100 and an Orion 100ED I'd be going for the Orion.....
With your Celestron 102mm refractor, the blue halo's may be chromatic abberation.. Im assuming its a Achromatic refractor... If this is the case, you will more than likely be able to correct this with a 2" Baader Semi APO filter (its on my wish-list for my 6" Achromat)
They are designed for this exact purpose..
Best of luck with your decision making!
