Did you get the impression the poor reliability is a standard thing, or just your set?
I tried several sets, and despite I had some very good ones, I always find them to lack responsiveness. It is still quick enough to do job very nicely but as I said I really don’t like the feel. My main concern being for the front mech that I find often to be poorly efficient. My previous X9 rear mech was just flawless, but again after trying ACROS shifters, I would not come back to cables.
Finally, concerning the rust, I don’t necessarily mean the cables but also the housings. When snow or mud get in there I have to remove everything, push the shit out of the housing, grease the cable so that it can again slide in smoothly and finally set up each derailleur, which is a pain. Maybe it is just me having shitty cable housing but that just adds to to the rest.
Regarding your second question Northwind, you cannot preset the positions. However, after a couple of rides you know how much you have to push the lever without even thinking about it and as I said you can get + or – one position when the chain rattles whithout changing the gears.