The Forward Components version is cheaper than the Exzentriker, but they both do the same job. Neither are cheap, but you don't have to pay for any frame modifications, you can easily go back to a geared set-up (if you leave the cable stops on the frame) and you have the fast, easy wheel removal with vertical dropouts. I use the Exzentriker and can recommend it without reservation.
And either would certainly look clean enough too, especially if you remove the cable stops . There's a BB closeup in the linked thread I think.
Got a P7 with semi horizontal dropouts (was supposed to have track ends but that's another story....). An old photo but think that it looks really clean and has worked well for me with no slipping wheel.