Question for those who know about open baffle speakers...

Last summer I heard a pair of DIY speakers and I was blown away by their transparency and their image ... They we're open baffle speakers with Scanspeak components powered by a mini DSP ... I did some research and find out that this was a design inspired by the Linkwitz LX 521. After reading quite a bit on the subject, I became interested in some manufacturers (Pure Audio, Spacial Audio, Tri-Art , ...) and noticed that some use dual concentric speakers. I know this kind of speaker well since I've been using Altec 604s for years. As open baffle technology is largely based on the principle of dipole speakers — speakers that emit sound both forward and backward — I wondered about the use of dual-concentric speakers. Indeed, as soon as the high-frequency driver comes into operation, there can no longer be any question of dipole in the case of a dual concentric speaker since the driver's back is closed. That leads me to think that these speaker's won't have the qualities that impressed me so much from those I heard last summer (which were dipole) What do you think?
I have not heard open baffle speakers that use a concentric done driver like this, but I I would share your concern. They could sound very good though. I have heard speakers that were partially open baffle but used a horn upper-mid-range/tweeter that sounded fabulous. 

Also, check out GR-Resesrch. I am using their NX-Otica open baffle speakers with their open baffle servo subs and they have excellent detail with a huge soundstage. 
I suspect that part of what impressed you was the control that DSP offers. All of our speakers are OB dipole and DSP controlled. Through development of our OB speakers we went through iterations of passive, analog active and DSP active. After a lengthy evaluation we decided DSP control was the best way forward for us.

IMHO, OB speakers have a "lack of constraint" quality which we prefer.