It seems like most companies are getting quite a bit of power (efficiency might be better) from their 13/14m kites these days. I can easily be powered on most brand's 13m kites (at my size) in 13 knots on a "small" board. So, the 13m Waroo isn't in a class of it's own in that regard.
I would go so far as to say if I wasn't totally powered up on a brand's 13/14m in 15 knots, I would consider it a p.o.s.

On the other hand, because I can just cruise around and sight-see on a Glide (or similar light wind board) on almost any SLE between 9m to 17m in solid 10 knots, I don't see the point in getting a BIG kite, when almost any kite will do if just cruising on a good LWB.

Since all I can do in ten knots is cruise around, putting up a bigger kite than what I am pretty powered up on in 13-15 knots doesn't make much sense to me anymore. Pretty sure you and Tom are saying almost the same thing (that a big kite, if you have a light wind board, isn't all that necessary anymore). Although Tom isn't big on riding in sub 15, I will a lot if it's nice outside.

Funny, 'cuz 4 years ago I had a 20m RRD. 20m !! lol.
I didn't have the Glide yet, though.