Here's my perspective on the Neptune. I was working for Maytag Corp when this machine was designed and first put on the market in 1997. I bought the first run of this washer myself and kept it for 6 years. During that time, Maytag was busy correcting design issues and making vast improvements on the MAH3000. Over the next 3 years, 4 more models showed up, each with significant improvement over previous designs. I actually gave up on my 3000 after I had: replaced the machine control & wax motor, replaced the motor control board and discovered a broken spinner support.
I promptly went and bought the latest model in 2003, the MAH5500 series. It had no wax motor and all the other issues had been dealt with as well. To date, it has not missed a lick and has not needed any attention. I have absolutely no traces of mildew nor any odors from the machine. (I take precautions) The main thing is that all the stuff you read about the Neptunes is mainly about the first run of these machines, and with due respect to Mayatg, the thing should have had a little more Quality control done before they released it for sale. Nowadays, the machine is basically trouble-free and is currently being made by Samsung for Maytag. I have since worked on the newest models and found only minor issues, mainly related to the installation and balance of the washer. I'm not promoting them over any other brand, I'm just saying that they are still a good brand to have today, compared to some of the others on the market.
You will hear some swear by Whirlpool, such as the Duet. I too believe this is a good product, and I give it second place in my list of choices to recommend. Mainly, the idea these days is to stick with a brand that you can easily get parts for later and repair. With help sites such as this one and my own, there is no logical reason why folks can't start fixing these things themselves to an extent and forget all those repair charges. There are instructional manuals on virtually everything these days, so include this reasoning when you go shopping.