Courtois has a recent design in this style ... the Grand Siecle trumpet with "Air Direct Column" - the valves are also set up so that on open notes, there are no 'bends' at any point (as opposed to, say, my Bach, which curves entering the 3rd valve, and also inside each valve).
I wrote all this with the intent of also providing a picture, but although the Courtois website still lists the horn on its Bb page, for some reason the picture is gone. Oh, and apparently Buffet just bought Courtois . . .
Whether the Direct-Air configuration affects play much, I couldn't say. It'd be interesting to see whether using the 3rd valve (and thereby introducing a couple bends) would have a noticeably different feel than an open note. Maybe there's a Courtois buff who can answer us all?
Here's the Courtois Bb page -
http://www.courtois-paris.com/panneautrpBb.html