I like charismatic, motivating instructors more than calm, sedate instructors.
I think age is relative.
Denise Austin does not "act her age" (I mean that in a good way as I think she's very inspiring to many).
Richard Simmons has always been wonderfully over the top.
Tony has his schtick and he's 52.
Debbie Siebers is now 50 (talk about an inspiring physique!!) and she's as warm & perky as ever.
Elizabeth Halfpapp is what 56-57 (another incredible physique!) she's more energetic on the Yogavibes workouts than the dvds.
Kathy Smith was a calmer instructor when she first started out, then she got a little "whoopy", then calm again.
Karen Voight was always calm, even when she started out.
Frankly, Burr puts me to sleep but that's due to her eternal set up time.
but she's in amazing shape.
Joan