Thanks for the advice on this one, I ordered the 103gr Omega and a new ZTW B series 45 AMP esc so I should be in good shape when the kit ships. I do have one more question, I have been going through the fourm on another site for the 42 slick and when the slick first came out everyone was going with the 72g Omega and there are lots of posts that said any motor over 90 grams is too heavy for the slick. Now everyone is recommending the 103gr Omega and I'm trying to figure out when and why the switch?? There are so many posts it's hard to weed out the facts on this one.
I think that flying styles have changed and that is the main difference. 3-4 years back I saw lots of people doing really low and slow moves. And the older v1 42" Slicks were built lighter with transparent covering on the bottom and lighter made landing gear. Then people started doing more things like pop tops, tumbles, and high speed moves, rifle rollers instead of slow harrier rolls, etc. So post stall performance becomes less important, and all up light weight was better. Also many people expressed a dislike for the transparent covering and weaker landing gear. So the plane was revised and these two things were addressed, and with the newer high energy flying style the bigger motor is nice, and now the overall plane weighs a couple ounces more than it used to. But it still flies great. I've flown and owned several older v1 42's, one setup with a light Omega 72, a couple with the Motrolfly which is 91 grams, and my last one had an Omega 103, and was a v2. My flying style has changed too, and I love the v2 one with the Omega 103. The weight is fine, fly the heck out of it!
But if all you like to do in 3d flying is really low and slow stuff you might benefit from the Omega 72, and choosing light components wherever possible.