From all the reading I've done, get a vented model dryer unit (either separate or combo). The non-vented units use a lot of water during the drying cycle. The vented units do not. Most reviewers that had used both also stated that the vented units dried faster and with less wrinkles.
I'm still looking at which ones to get for my 5th wheel. I've got the space to go with either a combo unit or separate units. Still haven't decided on anything other than it has to be the vented dryer.
2013 Columbus 3600TH
2015 GMC 3500 Denali TV
Toys: Victory Cross Country Tour and Victory Vegas 8-Ball