The Elkheart is a great bow! The standard core lamination is not carbon, its uni-weft glass. Gregg might offer a carbon core, but you'd have to ask him. Mine is the standard uni-weft, and while it's not the quietest LB I've heard, it's certainly not the loudest. I shot over the back of a walking 8pt last year with multiple other deer around, one doe was only about 10yds from my stand, and NONE of the deer reacted to the shot! The buck never broke stride, and only looked towards the arrow that hit the dirt beyond him.
Mine is a 54", 51#@28", that I draw about 27.5". I find the bow to be well mannered, pointable, smooth drawing, and respectably quick and quiet. The grip is good and repeatable. Greggs craftsmanship and fit and finish is among the very best in the business. I think you will be very pleased with an Elkheart, especially if you are accostomed to shooting this style of bow.
If I were to get another one, I would go with a 56" and two piece for the added mass weight. While my 54" certainly does not stack at my DL, the string angle is a frog hair more than I'd like. I wouldn't call it unpleasant by any means, but noticeable.