I'm beginning to think that this is the bottom line. Based on my own experience, I've had to replace a Moen cartridge once in 10 years (not a terrible record) on a prior faucet, and since Delta switched to ceramic cartridges I suspect they are better but I have no real experience. However...
We ordered two faucets that my wife liked, one from Delta and one from Moen. These are "pro" faucets and not big-box specials. Just cracked open the boxes and attempted installs.
We much prefer the finish and look of the Delta, but I have never seen more internal plastic construction in my life. Delta used all solid PEX supply lines, plastic fittings on all of the hoses, and the under-sink backing plate used to secure the faucet to the sink deck is also plastic. The threaded tube that holds the faucet to the backing plate underneath is metal, but does not appear to be brass, and is offset from center to permit all of the inflexible PEX to exit from the faucet body in one place; as a result, when the faucet body is tightened down on the sink deck, the mounting force is biased slightly to one side. Since the deck gasket that Delta includes doesn't sit under the faucet securely, once everything is tightened down with the bias to the off-center mounting tube, the gasket is unevenly compressed and tends to slip out to one side; it is slight, but noticeable if closely inspected, which I fear over time could let water past it or simply cause the gasket to slip out and the faucet to become loose. The braided hose for the pull down faucet head is thin, cheap, and easily kinks so that if the faucet head is pulled out too far, or is angled too much (if spraying out the sink, for example), the flow of water slows or stops. The switch on the faucet head feels cheap and doesn't seem to switch the spray/stream action as positively as what I've experienced on Moens in the past. A really poor design with chintzy parts, in my opinion. On the plus side, Delta claims to use a ceramic cartridge (supposedly better), they appear to use o-rings everywhere rather than washers, and we like the magnetic dock of the pull down faucet head. Also, the faucet head reaches out slightly more than the Moen into our sink, which means that there is slightly less of a reach forward to wash hands, etc. This faucet claims a 1.8gpm flow rate.
The Moen is a similar design, and appears to use slightly less plastic. The supply lines are braided plastic hoses, which are much easier to manipulate, but they also use traditional washers instead of o-rings at the connection points (had problems with leaks here on a prior Moen faucet, which were eventually corrected with replacement parts). All of the hose ends are brass, including the faucet head hose. The tube which anchors the sink extends up through the body and appears to be brass, and is centered on the body, which means that when tightened to the sink deck the faucet is pulled uniformly on the deck gasket. The under-sink backing plate is steel and anchors the base of the faucet firmly. Moen is a bit coy about the construction of their cartridge, but I suspect that it is a more traditional non-ceramic design which will eventually start to leak and need to be serviced or replaced. The finish on the Moen is not as uniform as that on the Delta, to the point where if we keep this one I will call Moen for a replacement part to see if I can get a more even finish. There is a black plastic bushing which keeps the neck of the faucet from contacting the base when the neck is rotated from side to side, and that was snapped in two right out of the box, but it is internal and the fact that it's split doesn't seem to affect its function. The valve, whatever it is, is much easier to operate (less force required) than that of the Delta, so it's easy to operate it with one finger or the back of the hand. The pull down faucet head doesn't "lock in" to the faucet arm with a magnet like the Delta, relying instead on the under-sink hose weight to hold it in place, and it doesn't pull out quite as far but the hose is fairly substantial and does not kink. The buttons on the faucet head to change from spray to stream seem more substantial and solid in operation than those of the Delta. The high arc faucet arm doesn't extend quite as far into the sink as the Delta (~1.5" less), so it is necessary to lean over a bit more to reach the water flow but it's not a big deal. This faucet claims a 1.5gpm flow rate, though it also has a "power boost" button which appears to increase the flow rate substantially (perhaps up to the normal 2.2gpm.)
At this point, I think that the pros of the Moen are slightly more than the pros of the Delta for us. I spent last night reading online reviews, and it appears that pretty much every faucet manufacturer (including the expensive European ones) are moving or have moved to more plastic construction than in the past, and some of the same issues that I've noticed with the Moen and Delta seem to plague some of the more expensive faucets as well. I guess you just have to pick something decent, hope for the best, and repair it when it breaks.
Thanks all for the input.
EDIT: Discovered that Moen's "Duralast" cartridge used in the faucet above is in fact a newer ceramic design and not their decades-old traditional cartridge.
JKG
