My objections were 1) remembering to change the filters, 2) the dripping of the waste water made from the process, 3) the bulky units themselves.
I pulled the tap on one that addresses all three of my biggest concerns: brondell's Circle H2O+ water filtration system (sic).
1) This system has four filters that is (somehow) monitored and has an indicator light on the handle. Blue led is good, red led is bad. The manual states to replace every six months, but usage should play a big factor on when they get replaced.
2) Reverse Osmosis removes some elements from the water and the waste goes down the sink drain using a supplied part. The ones I've seen drip almost constantly, while this brondell (sic) model flushes the waste only when used. brondell states the savings is considerable.
3) My last objection is the bulk of other units. brondell's unit looks like a mini p.c. case with the tubes all neatly ordered. See pictures below.
The spout itself is really nice. It's a 10" tall goose neck with a very smooth handle reminiscent of some expensive European faucet. I used the sink's dishwasher air gap hole that was unused anyway.
All the parts I needed were supplied in the box including a sturdy ball valve. It took me less than an hour to install, but that's me and doesn't include the pre-fill and flushing all systems require.
I've had it for a day and it's good, so far. The taste is adequate and far better than regular tap water. I like my water at room temperature: not too cold and not too hot. I guess I will fill a glass jug and store it in the fridge for picky drinkers.
never forget flight 93--the real heroes of 09/11/2001.