Hi
i have. Fhoenix. Currently using it on a 12,2HH pony but only until I can get a saddle fitter out.
it fits her nicely and she goes well in it but I now prefer the stability on a treed saddle. It didnāt fit my traditional cob well at all. He has a much broader back and it would have needed shimming in order for it not to tip the rider forward.
treeless saddles should still be fitted by an expert as they do usually need some form of shimming.
I find the Fhoenix very comfortable and easy to ride it. Very lightweight. Downsides are that itās difficult to mount from the ground when out hacking, the saddle can sometimes slip if on a big barrelled horse, no way would I attempt a decent size jump in one, but ok for schooling, dressage and hacking.
no experience of the other one.