Rubberlips wrote:It would be interesting to see a photo of your right arm and hand in playing position (lips on mouthpiece, fingers on levers).
I am current owner of the actual helicon that figures in some of the discussions you may have seen, a Lignatone Eb. (I'd like to post a picture of it here, hopefully this weekend I can get a shot of it from the same angle. Very similar. I'm surprised to hear it might be older than me - doesn't look it, and Søren's sure doesn't.)
My "avatar" image at this time is me, playing the Lignatone Eb. You won't see much detail, and maybe some spurious detail (I don't have a Charlie Chaplin mustache), but you get an idea of how it sits on me. I'm 6'2'', and fairly flexible. It's reasonably comfortable for me, on marches, standing, sitting, whatever, no real troubles, but your mileage might vary.
I believe this tuba may be similar in design to the current Cerveny Eb helicon, but I've never seen a picture of it. It's similar to Søren's, but his has probably significant differences in the placement of the valve section - it's a little more like duckskiff's Eb, I think - and that could make a noticeable difference. The Cerveny F helicon is quite different, because the bugle doesn't make a circle; it tends to fit easier, and it naturally hangs upright on you, which makes a bigger difference than you might think. American helicons don't always fit the best either, from what I've read, but at least they usually have a sousaphone style receiver, which may be floppy and leaky but at least is adjustable.
So it depends.