Are you sure that it makes it more acidic? AFAIK it only outputs pure H20, should be neutral. If you feed it alkaline water you'll get "more acidic" water, but the other way if you feed it acidic water.
I know pressure drops. The problem is knowing which filter is the one causing it in particular. Also, filters that are spent at different rates are a PITA. What I mean is if you are going to feed it nominally clean tap water, there's no reason to protect a catridge with equally or more expensive cartridges. Just use the RO filter and be done with it.
True. But have tasted distilled water? Tastes metalic. Probably just my imagination but I feel like it pulls stuff from the mucous in your mouth and tastes like blood.
Some units give you different fixed timespans for each. For that reason, I just use the Reverse Osmosis stage and ignore the rest. RO is the last step, and in theory it renders pure water meaning the only reason to have the previous ones is to pre-filter somewhat the water and extend the RO cartridge lifespan. Problem with that is, first, there's no way to gauge when each filter is spent. Second, they're priced the same anyway, so why even bother. Just go straight from tap to RO! Keep the post re-mineralization stage if you want.