I've very happily used Gevenalle units touring for years now, but am not familiar with their hydro setups.
I ride sti and trigger shifter bikes, and the Gevenalle setup is intuitive and natural feeling, it will be faster than bar ends in real life use, as intended you shift from the hoods which is nice, but they arent as fast and snappy as sti shifters obvoiusly simply due to the ergonomics of having to move your fingers physically more to shift.
I guess this is going to come down to what you are willing to spend isnt it?
Sti setups are pricey, and I don't even know what options you have (the new "gravel" groupsets I imagine)
Unfortunately, you just dont see Gevenalle bikes around much, so not easy to try out. When setting up my tough touring bike, I took a chance and tried them, figured I would sell them if I didnt like how they worked, but I took to them in about a minute, and love them still after spending many months traveling on this bike over the last 3 years or so on multiple long trips.
other plus is that they are simple, tough, and have an inexpensive "rebuild" policy if you trash them totally--they were and are aimed at cross racers.