Thanks for the reply - very helpful! At least Subsonic is now one option less to consider :-)
My plan is to convert my hybrid road/tri-bike (see attachment) to full tri and to clean up the cockpit while doing so. Though my front has a high stack (190mm) I still have approx 8cm drop to the pads which currently is OK for me. However by taking out the last 10mm spacer and switch to 17° stem (e.g. Aeria Ultimate) I could still go lower (should my body ever allow me ;-) ).
Cockpit-wize this leaves three options:
1. full integrated (e.g. Aeria Ultimate Stem/Bar/Hydration), Stem as low as possible and stack the armrests/extensions. This would put the hydration and gusset down, making it look clean. But does that really improve Aero as my arms (PLUS hydration!) are still above?
2. like option 1, but stack the stem so that the hydration is close to or even between extensions. Goal would be to hide the hydration from the wind and "expose" full steerer tube instead
3. conventional Flatbar (or 3T REVO) with Clip-Ons (e.g. Sonic) and BTA Hydration like PD FC/HC. That would be most flexible... and I am not sure if there really is an aero penalty.
If possible I want to avoid undermount, so 1. might even work without stacking the armrests.
Any thoughts? BTW, if this is too Off-Topic please let me know and I´ll move this topic to a new thread.
Thanks, Tobi