That valve looks like a half inch valve. I suppose it could be faster if you're using a hose to help with the siphon pressure.
As far as water adjustments, if you're only going to add some minerals and not using acid to adjust pH, then it won't take long. Plus, unless you're always going to add the same mineral adjustments you'll have to take time, at least the first time you brew the beer, to figure out what adjustments to make. Also, if you're not taking the time to measure the resulting pH, it won't take long (EDIT: I suppose the pH testing is done during the mash, but I also have other things to do in that time.).
EDIT: Also, you must not do yeast starters or just direct pitch dry yeast?
Yeah the hose helps a lot. Regardless, my individual times might be off slightly, but I know the total time is correct because SWMBO would harass me more if I went over time.