I've had the Kensington SE in my system for 2 years now. I've also heard the 2 Glenair models. I fell hard for the Tannoy sound a while ago, and though I do enjoy the attributes of certain other speakers, the dual-concentric sound has become deeply ingrained in my hi-fi experiences & perspectives. It's hard to imagine going to a different speaker line anymore. An example of some attributes I've enjoyed from other speakers (in every case these setups were lovingly tweaked and used excellent upstream gear):
* Audio Physic Tempo 25 threw an incredible soundstage
* Harbeth 40.1 were awesomely musical at moderate volumes
* YG Carmels were very fast and resolving
Then on the other hand, I've heard big boys like the Wilson Maxx and McIntosh line arrays at a high-end dealer, and walked away unimpressed in all respects - hard to compare since that was an open house event and seemed to be more "right from the can onto your plate" system setups (though the upstream gear was all hellaciously expensive). The lone speaker I was impressed by at that open house: the B&W Diamond Signature mini floor-stander. It actually reminded me more of a Tannoy, sound-wise.
What Tannoy does for me is a lovely mix of dynamics, resolution, musicality, coherence, and imaging. Most importantly, they can do spectacularly with rock recordings at higher volume levels. My vinyl collection is NOT typical audiophile fare. They can play clean & loud, and give you a non-fatiguing sound that's listenable for hours. This is all dependent on the room & system of course, as I'd occasionally been fighting a bit of brightness on my Kensingtons, with stock (Russian) tubes and modern high power PPP tube gear. On the other hand, they can easily swing to the side of "too warm and thick" with vintage tube gear, and/or more than 1 set of Mullards in the chain. In that sense they're FAR more revealing and sensitive than I'd ever expected. Every tube and component change is major and extremely apparent! You have to get the overall system balance right.
The Glenairs are excellent, but the Kensingtons SE has a bit of midrange magic that wins me over every time - heard as a touch of "sweetness", ala the upper line Koetsus. The Glenairs can be considered a touch more neutral, or a touch more dry, depending on your perspective. I was really shocked at how much the 10" version improved with some real power behind it - the Rogue Apollo monoblocks brought them alive and made them sound much more powerful than their modest size would indicate. I've got a couple of friends that actually prefer the 10" model over the 15", citing the midrange as the reason (one of them has a theory that the 10" dual concentric is the sweet spot for midrange). That said, the 15" model was certainly dynamic as all hell with those same Apollos.
The other alternative of course, is to consider running SET with these speakers - an avenue I've not explored. Lowest I've gone is 25 Watt/ch vintage PP....and unless in a small room, I love having the extra power!
Oh, and I definitely prefer the Prestige to the lower Tannoy lines, no question.