Race ski for J5

Question
Hi, my son is 53 inches and 62lbs and will be 10 this winter.  He has been
skiing on  Rossignol Radical RSX 130 skis for the past 2 winters.  He did
very well as a J6 last winter in VT.  He loves his Rossignol Radicals, but
we can't decide how long to go, stay at 130 for a 3rd year or go to a 140.  
He prefers GS over slalom.  He is an excellent skier.  What do you
recommend?  Also ibox plate or not?  He hasn't had a plate but he goes
so far on his edges we were wondering if this would be beneficial.  Thank
you.  

Answer
Dear Elaine --

How much has your son grown since he last skied?  Has he increased weight significantly since last winter?

If he really rides on his edges, I recommend the plate to keep his ski-boot edges up out of the snow when he is in a high speed tightly carved turn.

I will be able to answer this question in more detail this weekend, after I receive your information on how his weight, height, oh and strength have changed.

Regards,
Cindy