best in-ceiling speakers

Dear Gents and Ladies,

I will greatly appreciate your advice to get best in-ceiling speakers.

I was suggested to go with THX Ultra-2 speakers for 5.1 home theatre.
It is not a separate HT room - The floor is open concept and the area is shared with dining and kitchen.

Speakers must be in-ceiling.

Please advise for the case when money is not an issue.

I looked around and found Polk Audio RTS100 and Klipsch KS-7502-THX:

It seems that both products were release quite a while ago so I am not sure.
Also, Polk RTS100 peaker is not quite seamless in ceiling and you can see a "cone" which I do not like. On another hand, Klipsch KS-7502-THX speaker is not angled and I feel it may be a problem to direct the sound towards listening position.

Some people recommend going with Paradigm Signature in ceiling.
Though I somehow feel that several drivers are better that a single driver (that what Paradigm Signature in-ceiling has).

There are also pretty expensive B&W square in-ceiling speakers which I have been considering:

,but it is not mentioned that they are THX Ultra-2 speakers.

Additionally, I came across Sonance cinema speakers: LCR1S and LCR.5S

, But it is also not mentioned that they are THX Ultra-2 speakers.

How important is it to have in-ceiling speakers to be THX Ultra-2 speakers?

I will greatly appreciate your help here.

Thank you so much for your help!
/ John
Easy one. Thiel PowerPoint 1.2 speakers.
There is no definitive "best" of anything. There are way too many variables involved. The "best" you can hope for is to find something that works well in your system. You can then say it's the "best" for you until you find something you think is better !!!!
I recently put in a pair of the Polk RTS 100 ceiling in a fourth system in my house (living room). The electronics are tubed SET, DAC, and sonos, all hidden in a cabinet. I absolutely love the sound of this system and the Polk speakers( I have not demo'ed any other in ceilings.) I think the Polks are hard to find since they are no longer made. However, a friend found a pair after her my system.

Hope this helps.
I helped a friend of mine with very high ceilings do his system and we used Linn Sekrets. They weren't inexpensive but coupled with a subwoofer and some time and setting the subwoofer to match the correct crossover point, it produced a very open, non-directional, full bodied sound stage.We had looked at Klipsh, Def.Tech and Paradigm before deciding on the Linn. Another brand you may want to include in your evaluation are the Revel Speakers. One abstacle that you encounter in this process is placement and wall cavitey prepartion. If this is a new home and the walls haven't been drywalled yet try to determine location and make appropiate modifications to the space now and your rewards will be clearly evident.
I've got the Linn Custom 104C in-ceiling speakers for my surround speakers in my HT system. They are a step-up from the Sekrits, I believe, and they sound great. However, I can't say I did a lot of shopping around. I already had Linn speakers in front and saw these on an open-box special on A'gon classifieds. However, they have the same 2k array drivers as the Linn Majik speakers (i.e., they are a 3-way speaker design).

That all being said, there are tons of good options available out there.
I seriously doubt the THX Ultra-2 rating means anything after you reach a certain level. I mean, the Thiels or Revels are going to sound great -- does it really matter if they've gone to the added expense of getting some rating attached to them (which, by the way, you pay extra for)? Best of luck.