You would be far better off with a small washer and the Whirlpool 24" dryer. With the dryer, you get a higher and more efficient air flow as well as a larger drum, plus you can be washing another load while the first is drying. If you are drying electrically on 120 volts, it is not going to be a fast operation any way you look at it, but the combo route is not for any but the most desperate of situations with twin bed linens and clothes, other than socks and underwear, that are sent to the cleaners.

The nice thing about having a separate portable  or 24" dryer is that it does not have to be near the plumbing like the washer does. Some people put the dryer in another room or even out on a balcony. They can be covered with a tablecloth when not in use.

One of the most noticed failures of the little toy combos is that the air circulator, usually a squirrel cage blower, quickly clogs up with the moist lint in the air. Full-size domestic combos that used a blower, like the WP made 29 inch machines, ran the fill flume through two positions in the blower housing to flush lint from the larger blower each time the machine filled. These do not do that and the blowers are smaller so the fins are placed closer together, making them clog faster . The little combos also do not have a very good service network so it might take some time to find someone who is able to service your machine and show you how, if you have the aptitude, to take it apart to get into the blower to periodically clean it yourself.

Drying in the combo and a portable dryer presupposes that you have two separate circuits able to handle the high amp draw of the machines, both of which take the full capacity of a 15 amp circuit when in use. This means that you don't have the refrigerator, a toaster oven or a window air conditioner on the same circuit. This is something many small or older apartments lack.

It is true that a vented combo does not have to be hooked up to the sink for hours while it washes and dries so even if it dries slowly, at least you have the ability to use your sink during the process.