I had a Splende 2000S in my 5'er. I loved it. A couple of things to think about. Weight, water, power, and convince.
Weight - an all in one weights less than a stackable, and takes up less storage room. Make sure you can afford the extra king pin weight.
Water - uses less water than a machine made for a stick house.
Power - One really needs 50A for a washer of any kind. 30A will work on an all in one, but one has to be careful of not using too many electrical appliances at one time.
Convince - It takes a while to learn how to use an rv washer. One can wash and dry a set of queen sheets, but you can only do 3 pairs of jeans at a time. They do not work like your machine at home. For best results use a laundry soap designed for front loading machines. I use cheer. 1 to 2 Tablespoons. And about a teaspoon for fabric softener. The timer to me, is my favorite feature. I load and set my machine in the morning. Go and do whatever, and it starts on its own. Later in the evening, I fold or hang up. And I'm done. A small load everyday works for me. Also by doing laundry on board, one doesn't have to go out on yucky raining night, or beautiful sunny day, cause you have no clean clothes. Also, you don't have to store dirty clothes, until you get to a laundry mat. But one still has to go to a laundry mat for washing quilts/blankets, and rugs.
Be aware that some RV parks in AZ, do not want you to use bleach or your on board machine.
I hope this helps to give you a better idea of what's involved using an RV washer.
Barb