Open Baffle Experience

One of the things that has prevented me from pursuing large front baffle designes (like Spatial, Pure Audio Project, Caintuk, etc.) is one of the same problems I hear with box speakers - reflections from the front baffle allow localization of the speaker, they don't 'disappear' so they sound like listening to speakers - ruining the 'being there' effect

Honestly I do not understand this problem. I get edge diffraction, but my speakers have 1/2" rounds on the edges and I defy anyone to tell me they can hear where the speaker is.  I've heard many other speakers that do a great job of disappearing as well, some with very narrow (Vandersteen) and some with broad baffles (SF Amati Heritage).  I've never felt this was an attribute of baffles which could not be dealt with.

@mwatsme - yes, I agree that a narrow baffle helps make the speakers disappear by reducing the front baffle reflections. I think the wave guide used by the X4 does reduce the affect, but probably doesn't eliminate it altogether. I listened to a few songs on them at Pacific Audio Fest and thought they had a nice sound stage, but I wasn't that familiar with the songs that were played. 

One of the things I like about GR-Research's designs is that they use a folded baffle design so that the front baffle is as narrow as possible while still providing more separation between the driver front and back wave, lowering the frequency at which cancellation starts to occur. Like the Linkwitz speakers, they do a nice job completely disappearing 

On the other hand, I do find the Spatial Audio speakers somewhat more attractive. They have a nice clean look. 

I've heard some very nice box speakers, but they were also VERY expensive. As a percentage of production cost, a lot more of the expense goes toward the cabinet in high quality box speakers. An open-baffle speaker with comparable quality drivers and crossovers can be made for a lot less. 

The PAP Quintet s in my 16x26x 12 room, 7.7 ft off front wall, create a complete disappearing act, profoundly deep imaging and hit me with sound hard enough from a 20 w amp that I feel no need to reproduce the memorex commercial of years past. Huge effortless wall of sound. Invited guests are constantly thrilled no matter how poor the recording quality as that 3-D wall of sound just takes over. 
im partial to bi-poles, dipoles,  however, having owned Quad 57’s until recently, Mirage M1’s. Only experience  boxes were the Ref 3A GV’s. With the PAPs, the quality of the bass is something I’ve never experienced in the prior designs. With these, Midas and highs can be tailored with the use of different widebanders. XO is easily accessible, can be tailored, upgraded with a screwdriver. I also have joined the permanent “no box” camp. 
GR- research may be next on the list. 

how does the sound of OB differ from IB? if i mounted speakers in a wall separating one room from another room with no direct communication between the adjoining rooms [no windows], would infinite baffle sound the same as open baffle? or is it the rear-wave "bounce" that is key to OB sound?

Try it!  You'll probably like it. Placement in the room can be critical. My best system is the Linkwitz 521 with one amp per speaker, eight amps in total. Very easy to build; no annoying joints to master! Enjoy the music.